21161974 has 16 divisors (see below), whose sum is σ = 33697296. Its totient is φ = 9932800.

The previous prime is 21161971. The next prime is 21161981. The reversal of 21161974 is 47916112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161971) 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, 21309 + ... + 22279.

It is an arithmetic number, because the mean of its divisors is an integer number (2106081).

Almost surely, 2^21161974 is an apocalyptic number.

21161974 is a deficient number, since it is larger than the sum of its proper divisors (12535322).

21161974 is a wasteful number, since it uses less digits than its factorization.

21161974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631.

The product of its digits is 3024, while the sum is 31.

The square root of 21161974 is about 4600.2145602135. The cubic root of 21161974 is about 276.5999255150.

The spelling of 21161974 in words is "twenty-one million, one hundred sixty-one thousand, nine hundred seventy-four".