64406891 has 2 divisors, whose sum is σ = 64406892. Its totient is φ = 64406890.

The previous prime is 64406887. The next prime is 64406893. The reversal of 64406891 is 19860446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64406891 - 2² = 64406887 is a prime.

Together with 64406893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64406893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32203445 + 32203446.

It is an arithmetic number, because the mean of its divisors is an integer number (32203446).

Almost surely, 2^64406891 is an apocalyptic number.

64406891 is a deficient number, since it is larger than the sum of its proper divisors (1).

64406891 is an equidigital number, since it uses as much as digits as its factorization.

64406891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 64406891 is about 8025.3903954886. The cubic root of 64406891 is about 400.8458994576.

It can be divided in two parts, 6440 and 6891, that added together give a palindrome (13331).

The spelling of 64406891 in words is "sixty-four million, four hundred six thousand, eight hundred ninety-one".