721700131 has 4 divisors (see below), whose sum is σ = 721764000. Its totient is φ = 721636264.

The previous prime is 721700117. The next prime is 721700149. The reversal of 721700131 is 131007127.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 721700131 - 2⁹ = 721699619 is a prime.

It is a super-2 number, since 2×721700131² = 1041702158170834322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721700101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9931 + ... + 39268.

It is an arithmetic number, because the mean of its divisors is an integer number (180441000).

Almost surely, 2^721700131 is an apocalyptic number.

721700131 is a deficient number, since it is larger than the sum of its proper divisors (63869).

721700131 is a wasteful number, since it uses less digits than its factorization.

721700131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63868.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 721700131 is about 26864.4771212842. The cubic root of 721700131 is about 896.9858554327.

Adding to 721700131 its reverse (131007127), we get a palindrome (852707258).

The spelling of 721700131 in words is "seven hundred twenty-one million, seven hundred thousand, one hundred thirty-one".