21112455 has 32 divisors (see below), whose sum is σ = 41577984. Its totient is φ = 8908416.

The previous prime is 21112433. The next prime is 21112547. The reversal of 21112455 is 55421112.

It is not a de Polignac number, because 21112455 - 2⁸ = 21112199 is a prime.

It is a super-2 number, since 2×21112455² = 891471512254050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6369 + ... + 9098.

It is an arithmetic number, because the mean of its divisors is an integer number (1299312).

Almost surely, 2^21112455 is an apocalyptic number.

21112455 is a deficient number, since it is larger than the sum of its proper divisors (20465529).

21112455 is a wasteful number, since it uses less digits than its factorization.

21112455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15495.

The product of its digits is 400, while the sum is 21.

The square root of 21112455 is about 4594.8291589568. The cubic root of 21112455 is about 276.3840091542.

Adding to 21112455 its reverse (55421112), we get a palindrome (76533567).

The spelling of 21112455 in words is "twenty-one million, one hundred twelve thousand, four hundred fifty-five".