64971421 has 2 divisors, whose sum is σ = 64971422. Its totient is φ = 64971420.

The previous prime is 64971407. The next prime is 64971457. The reversal of 64971421 is 12417946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64802500 + 168921 = 8050^2 + 411^2 .

It is a cyclic number.

It is not a de Polignac number, because 64971421 - 2⁷ = 64971293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64971121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32485710 + 32485711.

It is an arithmetic number, because the mean of its divisors is an integer number (32485711).

Almost surely, 2^64971421 is an apocalyptic number.

It is an amenable number.

64971421 is a deficient number, since it is larger than the sum of its proper divisors (1).

64971421 is an equidigital number, since it uses as much as digits as its factorization.

64971421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 64971421 is about 8060.4851590956. The cubic root of 64971421 is about 402.0136398761.

The spelling of 64971421 in words is "sixty-four million, nine hundred seventy-one thousand, four hundred twenty-one".