20515974 has 32 divisors (see below), whose sum is σ = 43708896. Its totient is φ = 6397440.

The previous prime is 20515967. The next prime is 20516009. The reversal of 20515974 is 47951502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19584 + ... + 20604.

It is an arithmetic number, because the mean of its divisors is an integer number (1365903).

Almost surely, 2^20515974 is an apocalyptic number.

20515974 is an abundant number, since it is smaller than the sum of its proper divisors (23192922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20515974 is a wasteful number, since it uses less digits than its factorization.

20515974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1240.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 20515974 is about 4529.4562587578. The cubic root of 20515974 is about 273.7562522289.

Subtracting 20515974 from its reverse (47951502), we obtain a triangular number (27435528 = T₇₄₀₇).

The spelling of 20515974 in words is "twenty million, five hundred fifteen thousand, nine hundred seventy-four".