64439971 has 2 divisors, whose sum is σ = 64439972. Its totient is φ = 64439970.

The previous prime is 64439957. The next prime is 64440011. The reversal of 64439971 is 17993446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64439971 - 2⁵ = 64439939 is a prime.

It is not a weakly prime, because it can be changed into another prime (64439941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32219985 + 32219986.

It is an arithmetic number, because the mean of its divisors is an integer number (32219986).

Almost surely, 2^64439971 is an apocalyptic number.

64439971 is a deficient number, since it is larger than the sum of its proper divisors (1).

64439971 is an equidigital number, since it uses as much as digits as its factorization.

64439971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The square root of 64439971 is about 8027.4510898541. The cubic root of 64439971 is about 400.9145138178.

The spelling of 64439971 in words is "sixty-four million, four hundred thirty-nine thousand, nine hundred seventy-one".