22721731 has 2 divisors, whose sum is σ = 22721732. Its totient is φ = 22721730.

The previous prime is 22721717. The next prime is 22721747. The reversal of 22721731 is 13712722.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 22721731 - 2⁷ = 22721603 is a prime.

It is a super-2 number, since 2×22721731² = 1032554119272722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 22721696 and 22721705.

It is not a weakly prime, because it can be changed into another prime (22722731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11360865 + 11360866.

It is an arithmetic number, because the mean of its divisors is an integer number (11360866).

Almost surely, 2^22721731 is an apocalyptic number.

22721731 is a deficient number, since it is larger than the sum of its proper divisors (1).

22721731 is an equidigital number, since it uses as much as digits as its factorization.

22721731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1176, while the sum is 25.

The square root of 22721731 is about 4766.7316895332. The cubic root of 22721731 is about 283.2351427537.

Subtracting from 22721731 its reverse (13712722), we obtain a palindrome (9009009).

The spelling of 22721731 in words is "twenty-two million, seven hundred twenty-one thousand, seven hundred thirty-one".