64999421 has 2 divisors, whose sum is σ = 64999422. Its totient is φ = 64999420.

The previous prime is 64999393. The next prime is 64999423. The reversal of 64999421 is 12499946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61795321 + 3204100 = 7861^2 + 1790^2 .

It is a cyclic number.

It is not a de Polignac number, because 64999421 - 2²² = 60805117 is a prime.

Together with 64999423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64999423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32499710 + 32499711.

It is an arithmetic number, because the mean of its divisors is an integer number (32499711).

Almost surely, 2^64999421 is an apocalyptic number.

It is an amenable number.

64999421 is a deficient number, since it is larger than the sum of its proper divisors (1).

64999421 is an equidigital number, since it uses as much as digits as its factorization.

64999421 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 64999421 is about 8062.2218401629. The cubic root of 64999421 is about 402.0713820091.

The spelling of 64999421 in words is "sixty-four million, nine hundred ninety-nine thousand, four hundred twenty-one".