64436772521 has 8 divisors (see below), whose sum is σ = 70334919264. Its totient is φ = 58545335520.

The previous prime is 64436772493. The next prime is 64436772583. The reversal of 64436772521 is 12527763446.

64436772521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 64436772521 - 2⁶ = 64436772457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64436772221) 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, 1657340 + ... + 1695773.

It is an arithmetic number, because the mean of its divisors is an integer number (8791864908).

Almost surely, 2^64436772521 is an apocalyptic number.

It is an amenable number.

64436772521 is a deficient number, since it is larger than the sum of its proper divisors (5898146743).

64436772521 is a wasteful number, since it uses less digits than its factorization.

64436772521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3354871.

The product of its digits is 1693440, while the sum is 47.

The spelling of 64436772521 in words is "sixty-four billion, four hundred thirty-six million, seven hundred seventy-two thousand, five hundred twenty-one".