1642665620 has 24 divisors (see below), whose sum is σ = 3474783144. Its totient is φ = 652269056.

The previous prime is 1642665569. The next prime is 1642665641. The reversal of 1642665620 is 265662461.

It can be written as a sum of positive squares in 4 ways, for example, as 1119364 + 1641546256 = 1058^2 + 40516^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 297017 + ... + 302496.

It is an arithmetic number, because the mean of its divisors is an integer number (144782631).

Almost surely, 2^1642665620 is an apocalyptic number.

1642665620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1642665620 is an abundant number, since it is smaller than the sum of its proper divisors (1832117524).

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

1642665620 is a wasteful number, since it uses less digits than its factorization.

1642665620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599659 (or 599657 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 1642665620 is about 40529.8114972177. The cubic root of 1642665620 is about 1179.9122840093.

The spelling of 1642665620 in words is "one billion, six hundred forty-two million, six hundred sixty-five thousand, six hundred twenty".