64402782721 has 4 divisors (see below), whose sum is σ = 65364018352. Its totient is φ = 63441547092.

The previous prime is 64402782707. The next prime is 64402782749. The reversal of 64402782721 is 12728720446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64402782721 - 2⁷ = 64402782593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64402782761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480617715 + ... + 480617848.

It is an arithmetic number, because the mean of its divisors is an integer number (16341004588).

Almost surely, 2^64402782721 is an apocalyptic number.

It is an amenable number.

64402782721 is a deficient number, since it is larger than the sum of its proper divisors (961235631).

64402782721 is an equidigital number, since it uses as much as digits as its factorization.

64402782721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961235630.

The product of its (nonzero) digits is 301056, while the sum is 43.

The spelling of 64402782721 in words is "sixty-four billion, four hundred two million, seven hundred eighty-two thousand, seven hundred twenty-one".