646723370880 has 128 divisors (see below), whose sum is σ = 2290478666400. Its totient is φ = 172459560960.

The previous prime is 646723370837. The next prime is 646723370963. The reversal of 646723370880 is 88073327646.

646723370880 is a `hidden beast` number, since 6 + 467 + 2 + 33 + 70 + 8 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×646723370880² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 18695781 + ... + 18730340.

Almost surely, 2^646723370880 is an apocalyptic number.

646723370880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646723370880 is an abundant number, since it is smaller than the sum of its proper divisors (1643755295520).

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

646723370880 is a wasteful number, since it uses less digits than its factorization.

646723370880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37426149 (or 37426131 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 54.

The spelling of 646723370880 in words is "six hundred forty-six billion, seven hundred twenty-three million, three hundred seventy thousand, eight hundred eighty".