721691448 has 32 divisors (see below), whose sum is σ = 1866445200. Its totient is φ = 232268288.

The previous prime is 721691441. The next prime is 721691449. The reversal of 721691448 is 844196127.

It is a super-2 number, since 2×721691448² = 1041677092232673408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721691441) 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 7 ways as a sum of consecutive naturals, for example, 517761 + ... + 519152.

Almost surely, 2^721691448 is an apocalyptic number.

It is an amenable number.

721691448 is an abundant number, since it is smaller than the sum of its proper divisors (1144753752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721691448 is a wasteful number, since it uses less digits than its factorization.

721691448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036951 (or 1036947 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 721691448 is about 26864.3155133348. The cubic root of 721691448 is about 896.9822581125.

The spelling of 721691448 in words is "seven hundred twenty-one million, six hundred ninety-one thousand, four hundred forty-eight".