20687974 has 16 divisors (see below), whose sum is σ = 32219136. Its totient is φ = 9952200.

The previous prime is 20687969. The next prime is 20687977. The reversal of 20687974 is 47978602.

It is a self number, because there is not a number n which added to its sum of digits gives 20687974.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20687977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10969 + ... + 12715.

It is an arithmetic number, because the mean of its divisors is an integer number (2013696).

Almost surely, 2^20687974 is an apocalyptic number.

20687974 is a deficient number, since it is larger than the sum of its proper divisors (11531162).

20687974 is a wasteful number, since it uses less digits than its factorization.

20687974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 20687974 is about 4548.4034561591. The cubic root of 20687974 is about 274.5191553128.

The spelling of 20687974 in words is "twenty million, six hundred eighty-seven thousand, nine hundred seventy-four".