21049025 has 12 divisors (see below), whose sum is σ = 27236352. Its totient is φ = 16106640.

The previous prime is 21049019. The next prime is 21049027. The reversal of 21049025 is 52094012.

It is not a de Polignac number, because 21049025 - 2⁶ = 21048961 is a prime.

It is a super-2 number, since 2×21049025² = 886122906901250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21049027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17729 + ... + 18878.

It is an arithmetic number, because the mean of its divisors is an integer number (2269696).

Almost surely, 2^21049025 is an apocalyptic number.

21049025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21049025 is a deficient number, since it is larger than the sum of its proper divisors (6187327).

21049025 is a wasteful number, since it uses less digits than its factorization.

21049025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36640 (or 36635 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21049025 is about 4587.9216427485. The cubic root of 21049025 is about 276.1069432588.

The spelling of 21049025 in words is "twenty-one million, forty-nine thousand, twenty-five".