721653164 has 12 divisors (see below), whose sum is σ = 1263934224. Its totient is φ = 360529104.

The previous prime is 721653161. The next prime is 721653209. The reversal of 721653164 is 461356127.

It is a super-2 number, since 2×721653164² = 1041566578222421792, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (721653161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68867 + ... + 78650.

It is an arithmetic number, because the mean of its divisors is an integer number (105327852).

Almost surely, 2^721653164 is an apocalyptic number.

It is an amenable number.

721653164 is a deficient number, since it is larger than the sum of its proper divisors (542281060).

721653164 is a wasteful number, since it uses less digits than its factorization.

721653164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148744 (or 148742 counting only the distinct ones).

The product of its digits is 30240, while the sum is 35.

The square root of 721653164 is about 26863.6029601392. The cubic root of 721653164 is about 896.9663969131.

The spelling of 721653164 in words is "seven hundred twenty-one million, six hundred fifty-three thousand, one hundred sixty-four".