21154725 has 36 divisors (see below), whose sum is σ = 38185056. Its totient is φ = 11195040.

The previous prime is 21154711. The next prime is 21154759. The reversal of 21154725 is 52745112.

It is not a de Polignac number, because 21154725 - 2⁴ = 21154709 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 37294 + ... + 37856.

It is an arithmetic number, because the mean of its divisors is an integer number (1060696).

Almost surely, 2^21154725 is an apocalyptic number.

21154725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21154725 is a deficient number, since it is larger than the sum of its proper divisors (17030331).

21154725 is a wasteful number, since it uses less digits than its factorization.

21154725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746 (or 738 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21154725 is about 4599.4265946963. The cubic root of 21154725 is about 276.5683389555.

Adding to 21154725 its reverse (52745112), we get a palindrome (73899837).

The spelling of 21154725 in words is "twenty-one million, one hundred fifty-four thousand, seven hundred twenty-five".