64429991 has 2 divisors, whose sum is σ = 64429992. Its totient is φ = 64429990.

The previous prime is 64429961. The next prime is 64430011. The reversal of 64429991 is 19992446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64429991 - 2¹⁰ = 64428967 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64429921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32214995 + 32214996.

It is an arithmetic number, because the mean of its divisors is an integer number (32214996).

Almost surely, 2^64429991 is an apocalyptic number.

64429991 is a deficient number, since it is larger than the sum of its proper divisors (1).

64429991 is an equidigital number, since it uses as much as digits as its factorization.

64429991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 44.

The square root of 64429991 is about 8026.8294487923. The cubic root of 64429991 is about 400.8938158288.

The spelling of 64429991 in words is "sixty-four million, four hundred twenty-nine thousand, nine hundred ninety-one".