21125394 has 32 divisors (see below), whose sum is σ = 47211840. Its totient is φ = 7001856.

The previous prime is 21125393. The next prime is 21125443. The reversal of 21125394 is 49352112.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21125393) 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, 9409 + ... + 11435.

It is an arithmetic number, because the mean of its divisors is an integer number (1475370).

Almost surely, 2^21125394 is an apocalyptic number.

21125394 is an abundant number, since it is smaller than the sum of its proper divisors (26086446).

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

21125394 is a wasteful number, since it uses less digits than its factorization.

21125394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2231 (or 2225 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21125394 is about 4596.2369390622. The cubic root of 21125394 is about 276.4404592826.

The spelling of 21125394 in words is "twenty-one million, one hundred twenty-five thousand, three hundred ninety-four".