64429921 has 2 divisors, whose sum is σ = 64429922. Its totient is φ = 64429920.

The previous prime is 64429907. The next prime is 64429957. The reversal of 64429921 is 12992446.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32901696 + 31528225 = 5736^2 + 5615^2 .

It is a cyclic number.

It is not a de Polignac number, because 64429921 - 2⁵ = 64429889 is a prime.

It is not a weakly prime, because it can be changed into another prime (64429961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32214960 + 32214961.

It is an arithmetic number, because the mean of its divisors is an integer number (32214961).

Almost surely, 2^64429921 is an apocalyptic number.

It is an amenable number.

64429921 is a deficient number, since it is larger than the sum of its proper divisors (1).

64429921 is an equidigital number, since it uses as much as digits as its factorization.

64429921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 64429921 is about 8026.8250884145. The cubic root of 64429921 is about 400.8936706450.

The spelling of 64429921 in words is "sixty-four million, four hundred twenty-nine thousand, nine hundred twenty-one".