1665650420 has 48 divisors (see below), whose sum is σ = 4095076608. Its totient is φ = 557149440.

The previous prime is 1665650411. The next prime is 1665650449. The reversal of 1665650420 is 240565661.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139352 + ... + 150831.

It is an arithmetic number, because the mean of its divisors is an integer number (85314096).

Almost surely, 2^1665650420 is an apocalyptic number.

1665650420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665650420 is an abundant number, since it is smaller than the sum of its proper divisors (2429426188).

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

1665650420 is a wasteful number, since it uses less digits than its factorization.

1665650420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290240 (or 290238 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 1665650420 is about 40812.3807195807. The cubic root of 1665650420 is about 1185.3900737704.

It can be divided in two parts, 16656 and 50420, that added together give a palindrome (67076).

The spelling of 1665650420 in words is "one billion, six hundred sixty-five million, six hundred fifty thousand, four hundred twenty".