20524921 has 4 divisors (see below), whose sum is σ = 21605200. Its totient is φ = 19444644.

The previous prime is 20524897. The next prime is 20524927. The reversal of 20524921 is 12942502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12942502 = 2 ⋅6471251.

It is a cyclic number.

It is not a de Polignac number, because 20524921 - 2⁷ = 20524793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20524927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540111 + ... + 540148.

It is an arithmetic number, because the mean of its divisors is an integer number (5401300).

Almost surely, 2^20524921 is an apocalyptic number.

It is an amenable number.

20524921 is a deficient number, since it is larger than the sum of its proper divisors (1080279).

20524921 is a wasteful number, since it uses less digits than its factorization.

20524921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080278.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20524921 is about 4530.4437972455. The cubic root of 20524921 is about 273.7960414070.

The spelling of 20524921 in words is "twenty million, five hundred twenty-four thousand, nine hundred twenty-one".