20972158 has 4 divisors (see below), whose sum is σ = 31458240. Its totient is φ = 10486078.

The previous prime is 20972141. The next prime is 20972167. The reversal of 20972158 is 85127902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85127902 = 2 ⋅42563951.

It is a super-2 number, since 2×20972158² = 879662822353928, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5243038 + ... + 5243041.

It is an arithmetic number, because the mean of its divisors is an integer number (7864560).

Almost surely, 2^20972158 is an apocalyptic number.

20972158 is a deficient number, since it is larger than the sum of its proper divisors (10486082).

20972158 is a wasteful number, since it uses less digits than its factorization.

20972158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10486081.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 20972158 is about 4579.5368761481. The cubic root of 20972158 is about 275.7704367828.

The spelling of 20972158 in words is "twenty million, nine hundred seventy-two thousand, one hundred fifty-eight".