64646023521 has 8 divisors (see below), whose sum is σ = 88297007904. Its totient is φ = 42046194080.

The previous prime is 64646023493. The next prime is 64646023537. The reversal of 64646023521 is 12532064646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64646023521 - 2¹⁷ = 64645892449 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64646023521.

It is not an unprimeable number, because it can be changed into a prime (64646023021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 262788591 + ... + 262788836.

It is an arithmetic number, because the mean of its divisors is an integer number (11037125988).

Almost surely, 2^64646023521 is an apocalyptic number.

It is an amenable number.

64646023521 is a deficient number, since it is larger than the sum of its proper divisors (23650984383).

64646023521 is a wasteful number, since it uses less digits than its factorization.

64646023521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525577471.

The product of its (nonzero) digits is 207360, while the sum is 39.

The spelling of 64646023521 in words is "sixty-four billion, six hundred forty-six million, twenty-three thousand, five hundred twenty-one".