646243252920 has 96 divisors (see below), whose sum is σ = 2118877347600. Its totient is φ = 170806465536.

The previous prime is 646243252867. The next prime is 646243252981. The reversal of 646243252920 is 29252342646.

646243252920 is a `hidden beast` number, since 6 + 4 + 62 + 43 + 2 + 529 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 7902330 + ... + 7983689.

Almost surely, 2^646243252920 is an apocalyptic number.

646243252920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646243252920 is an abundant number, since it is smaller than the sum of its proper divisors (1472634094680).

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

646243252920 is a wasteful number, since it uses less digits than its factorization.

646243252920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15886149 (or 15886142 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 646243252920 in words is "six hundred forty-six billion, two hundred forty-three million, two hundred fifty-two thousand, nine hundred twenty".