721362731 has 4 divisors (see below), whose sum is σ = 752726352. Its totient is φ = 689999112.

The previous prime is 721362727. The next prime is 721362737. The reversal of 721362731 is 137263127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 721362731 - 2² = 721362727 is a prime.

It is a super-2 number, since 2×721362731² = 1040728379351556722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721362737) 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, 15681776 + ... + 15681821.

It is an arithmetic number, because the mean of its divisors is an integer number (188181588).

Almost surely, 2^721362731 is an apocalyptic number.

721362731 is a deficient number, since it is larger than the sum of its proper divisors (31363621).

721362731 is a wasteful number, since it uses less digits than its factorization.

721362731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31363620.

The product of its digits is 10584, while the sum is 32.

The square root of 721362731 is about 26858.1967190651. The cubic root of 721362731 is about 896.8460511985.

The spelling of 721362731 in words is "seven hundred twenty-one million, three hundred sixty-two thousand, seven hundred thirty-one".