64707021 has 6 divisors (see below), whose sum is σ = 93465710. Its totient is φ = 43138008.

The previous prime is 64707001. The next prime is 64707023. The reversal of 64707021 is 12070746.

It can be written as a sum of positive squares in only one way, i.e., 57972996 + 6734025 = 7614^2 + 2595^2 .

It is not a de Polignac number, because 64707021 - 2²² = 60512717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64707023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3594826 + ... + 3594843.

Almost surely, 2^64707021 is an apocalyptic number.

It is an amenable number.

64707021 is a deficient number, since it is larger than the sum of its proper divisors (28758689).

64707021 is a wasteful number, since it uses less digits than its factorization.

64707021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7189675 (or 7189672 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 64707021 is about 8044.0674412886. The cubic root of 64707021 is about 401.4675694316.

Adding to 64707021 its reverse (12070746), we get a palindrome (76777767).

The spelling of 64707021 in words is "sixty-four million, seven hundred seven thousand, twenty-one".