21121044 has 48 divisors (see below), whose sum is σ = 58146816. Its totient is φ = 5839200.

The previous prime is 21121033. The next prime is 21121063. The reversal of 21121044 is 44012112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1452 + ... + 6659.

It is an arithmetic number, because the mean of its divisors is an integer number (1211392).

Almost surely, 2^21121044 is an apocalyptic number.

It is an amenable number.

21121044 is an abundant number, since it is smaller than the sum of its proper divisors (37025772).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121044 is a wasteful number, since it uses less digits than its factorization.

21121044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8156 (or 8154 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 21121044 is about 4595.7637014973. The cubic root of 21121044 is about 276.4214837225.

Adding to 21121044 its reverse (44012112), we get a palindrome (65133156).

The spelling of 21121044 in words is "twenty-one million, one hundred twenty-one thousand, forty-four".