21049625 has 16 divisors (see below), whose sum is σ = 27655680. Its totient is φ = 15951600.

The previous prime is 21049597. The next prime is 21049627. The reversal of 21049625 is 52694012.

It is a happy number.

It is not a de Polignac number, because 21049625 - 2²⁴ = 4272409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21049627) 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, 2057 + ... + 6806.

It is an arithmetic number, because the mean of its divisors is an integer number (1728480).

Almost surely, 2^21049625 is an apocalyptic number.

21049625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21049625 is a deficient number, since it is larger than the sum of its proper divisors (6606055).

21049625 is an equidigital number, since it uses as much as digits as its factorization.

21049625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8897 (or 8887 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21049625 is about 4587.9870313679. The cubic root of 21049625 is about 276.1095666993.

The spelling of 21049625 in words is "twenty-one million, forty-nine thousand, six hundred twenty-five".