721982947 has 4 divisors (see below), whose sum is σ = 825123376. Its totient is φ = 618842520.

The previous prime is 721982923. The next prime is 721982953. The reversal of 721982947 is 749289127.

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 721982947 - 2²³ = 713594339 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721982947.

It is not an unprimeable number, because it can be changed into a prime (721982977) 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, 51570204 + ... + 51570217.

It is an arithmetic number, because the mean of its divisors is an integer number (206280844).

Almost surely, 2^721982947 is an apocalyptic number.

721982947 is a deficient number, since it is larger than the sum of its proper divisors (103140429).

721982947 is a wasteful number, since it uses less digits than its factorization.

721982947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103140428.

The product of its digits is 508032, while the sum is 49.

The square root of 721982947 is about 26869.7403597430. The cubic root of 721982947 is about 897.1030088093.

It can be divided in two parts, 72198 and 2947, that multiplied together give a triangular number (212767506 = T₂₀₆₂₈).

The spelling of 721982947 in words is "seven hundred twenty-one million, nine hundred eighty-two thousand, nine hundred forty-seven".