64472921 has 6 divisors (see below), whose sum is σ = 64837722. Its totient is φ = 64109360.

The previous prime is 64472917. The next prime is 64472929. The reversal of 64472921 is 12927446.

It can be written as a sum of positive squares in only one way, i.e., 58736896 + 5736025 = 7664^2 + 2395^2 .

It is not a de Polignac number, because 64472921 - 2² = 64472917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64472929) 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 in 5 ways as a sum of consecutive naturals, for example, 134360 + ... + 134838.

It is an arithmetic number, because the mean of its divisors is an integer number (10806287).

Almost surely, 2^64472921 is an apocalyptic number.

It is an amenable number.

64472921 is a deficient number, since it is larger than the sum of its proper divisors (364801).

64472921 is an frugal number, since it uses more digits than its factorization.

64472921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1239 (or 760 counting only the distinct ones).

The product of its digits is 24192, while the sum is 35.

The square root of 64472921 is about 8029.5031602211. The cubic root of 64472921 is about 400.9828351929.

The spelling of 64472921 in words is "sixty-four million, four hundred seventy-two thousand, nine hundred twenty-one".