20974251 has 4 divisors (see below), whose sum is σ = 27965672. Its totient is φ = 13982832.

The previous prime is 20974249. The next prime is 20974253. The reversal of 20974251 is 15247902.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20974249) and next prime (20974253).

It is not a de Polignac number, because 20974251 - 2¹ = 20974249 is a prime.

It is a super-2 number, since 2×20974251² = 879838410022002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20974253) 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, 3495706 + ... + 3495711.

It is an arithmetic number, because the mean of its divisors is an integer number (6991418).

Almost surely, 2^20974251 is an apocalyptic number.

20974251 is a deficient number, since it is larger than the sum of its proper divisors (6991421).

20974251 is an equidigital number, since it uses as much as digits as its factorization.

20974251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6991420.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 20974251 is about 4579.7653870040. The cubic root of 20974251 is about 275.7796103472.

The spelling of 20974251 in words is "twenty million, nine hundred seventy-four thousand, two hundred fifty-one".