22121531 has 2 divisors, whose sum is σ = 22121532. Its totient is φ = 22121530.

The previous prime is 22121521. The next prime is 22121543. The reversal of 22121531 is 13512122.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 22121531 - 2¹⁰ = 22120507 is a prime.

It is a super-2 number, since 2×22121531² = 978724267567922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (22121521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11060765 + 11060766.

It is an arithmetic number, because the mean of its divisors is an integer number (11060766).

Almost surely, 2^22121531 is an apocalyptic number.

22121531 is a deficient number, since it is larger than the sum of its proper divisors (1).

22121531 is an equidigital number, since it uses as much as digits as its factorization.

22121531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120, while the sum is 17.

The square root of 22121531 is about 4703.3531655618. The cubic root of 22121531 is about 280.7189474685.

Adding to 22121531 its reverse (13512122), we get a palindrome (35633653).

The spelling of 22121531 in words is "twenty-two million, one hundred twenty-one thousand, five hundred thirty-one".