721497 has 32 divisors (see below), whose sum is σ = 1216512. Its totient is φ = 370944.

The previous prime is 721481. The next prime is 721499. The reversal of 721497 is 794127.

It is not a de Polignac number, because 721497 - 2⁴ = 721481 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721497.

It is not an unprimeable number, because it can be changed into a prime (721499) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15328 + ... + 15374.

It is an arithmetic number, because the mean of its divisors is an integer number (38016).

2⁷²¹⁴⁹⁷ is an apocalyptic number.

It is an amenable number.

721497 is a deficient number, since it is larger than the sum of its proper divisors (495015).

721497 is a wasteful number, since it uses less digits than its factorization.

721497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117.

The product of its digits is 3528, while the sum is 30.

The square root of 721497 is about 849.4097950930. The cubic root of 721497 is about 89.6901691792.

Multiplying 721497 by its sum of digits (30), we get a triangular number (21644910 = T₆₅₇₉).

The spelling of 721497 in words is "seven hundred twenty-one thousand, four hundred ninety-seven".