721572977 has 2 divisors, whose sum is σ = 721572978. Its totient is φ = 721572976.

The previous prime is 721572961. The next prime is 721573057. The reversal of 721572977 is 779275127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 699285136 + 22287841 = 26444^2 + 4721^2 .

It is a cyclic number.

It is not a de Polignac number, because 721572977 - 2⁴ = 721572961 is a prime.

It is a super-2 number, since 2×721572977² = 1041335122273285058, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721572277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360786488 + 360786489.

It is an arithmetic number, because the mean of its divisors is an integer number (360786489).

Almost surely, 2^721572977 is an apocalyptic number.

It is an amenable number.

721572977 is a deficient number, since it is larger than the sum of its proper divisors (1).

721572977 is an equidigital number, since it uses as much as digits as its factorization.

721572977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432180, while the sum is 47.

The square root of 721572977 is about 26862.1104345880. The cubic root of 721572977 is about 896.9331733313.

The spelling of 721572977 in words is "seven hundred twenty-one million, five hundred seventy-two thousand, nine hundred seventy-seven".