20151974 has 4 divisors (see below), whose sum is σ = 30227964. Its totient is φ = 10075986.

The previous prime is 20151973. The next prime is 20151983. The reversal of 20151974 is 47915102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47915102 = 2 ⋅23957551.

It is a super-2 number, since 2×20151974² = 812204112193352, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20151973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5037992 + ... + 5037995.

It is an arithmetic number, because the mean of its divisors is an integer number (7556991).

Almost surely, 2^20151974 is an apocalyptic number.

20151974 is a deficient number, since it is larger than the sum of its proper divisors (10075990).

20151974 is a wasteful number, since it uses less digits than its factorization.

20151974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10075989.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 20151974 is about 4489.0950090191. The cubic root of 20151974 is about 272.1275623551.

It can be divided in two parts, 2015 and 1974, that multiplied together give a triangular number (3977610 = T₂₈₂₀).

The spelling of 20151974 in words is "twenty million, one hundred fifty-one thousand, nine hundred seventy-four".