64920641 has 4 divisors (see below), whose sum is σ = 65356500. Its totient is φ = 64484784.

The previous prime is 64920629. The next prime is 64920659. The reversal of 64920641 is 14602946.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14602946 = 2 ⋅7301473.

It can be written as a sum of positive squares in 2 ways, for example, as 24216241 + 40704400 = 4921^2 + 6380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64920641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64920598 and 64920607.

It is not an unprimeable number, because it can be changed into a prime (64920041) 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, 217706 + ... + 218003.

It is an arithmetic number, because the mean of its divisors is an integer number (16339125).

Almost surely, 2^64920641 is an apocalyptic number.

It is an amenable number.

64920641 is a deficient number, since it is larger than the sum of its proper divisors (435859).

64920641 is a wasteful number, since it uses less digits than its factorization.

64920641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435858.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 64920641 is about 8057.3346089138. The cubic root of 64920641 is about 401.9088780539.

The spelling of 64920641 in words is "sixty-four million, nine hundred twenty thousand, six hundred forty-one".