722987781 has 16 divisors (see below), whose sum is σ = 1022042304. Its totient is φ = 453037824.

The previous prime is 722987779. The next prime is 722987827. The reversal of 722987781 is 187789227.

It is a happy number.

It is not a de Polignac number, because 722987781 - 2¹ = 722987779 is a prime.

It is a super-2 number, since 2×722987781² = 1045422662950607922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (722987701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31131 + ... + 49143.

It is an arithmetic number, because the mean of its divisors is an integer number (63877644).

Almost surely, 2^722987781 is an apocalyptic number.

It is an amenable number.

722987781 is a deficient number, since it is larger than the sum of its proper divisors (299054523).

722987781 is a wasteful number, since it uses less digits than its factorization.

722987781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18820.

The product of its digits is 790272, while the sum is 51.

The square root of 722987781 is about 26888.4321037877. The cubic root of 722987781 is about 897.5190028125.

The spelling of 722987781 in words is "seven hundred twenty-two million, nine hundred eighty-seven thousand, seven hundred eighty-one".