1651660660 has 48 divisors (see below), whose sum is σ = 3757496400. Its totient is φ = 609827712.

The previous prime is 1651660651. The next prime is 1651660669. The reversal of 1651660660 is 660661561.

It is an interprime number because it is at equal distance from previous prime (1651660651) and next prime (1651660669).

It can be written as a sum of positive squares in 8 ways, for example, as 1109422864 + 542237796 = 33308^2 + 23286^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1651660669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25146 + ... + 62734.

It is an arithmetic number, because the mean of its divisors is an integer number (78281175).

Almost surely, 2^1651660660 is an apocalyptic number.

1651660660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1651660660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1878748200).

1651660660 is an abundant number, since it is smaller than the sum of its proper divisors (2105835740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1651660660 is a wasteful number, since it uses less digits than its factorization.

1651660660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37637 (or 37609 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 1651660660 is about 40640.6281939637. The cubic root of 1651660660 is about 1182.0620508861.

Subtracting from 1651660660 its reverse (660661561), we obtain a palindrome (990999099).

The spelling of 1651660660 in words is "one billion, six hundred fifty-one million, six hundred sixty thousand, six hundred sixty".