1640715020 has 72 divisors (see below), whose sum is σ = 4146312240. Its totient is φ = 543123840.

The previous prime is 1640715019. The next prime is 1640715061. The reversal of 1640715020 is 205170461.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 446 + ... + 57285.

It is an arithmetic number, because the mean of its divisors is an integer number (57587670).

Almost surely, 2^1640715020 is an apocalyptic number.

1640715020 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 1640715020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2073156120).

1640715020 is an abundant number, since it is smaller than the sum of its proper divisors (2505597220).

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

1640715020 is a wasteful number, since it uses less digits than its factorization.

1640715020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57783 (or 57774 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 1640715020 is about 40505.7405808115. The cubic root of 1640715020 is about 1179.4450660782.

Adding to 1640715020 its reverse (205170461), we get a palindrome (1845885481).

The spelling of 1640715020 in words is "one billion, six hundred forty million, seven hundred fifteen thousand, twenty".