21180974 has 4 divisors (see below), whose sum is σ = 31771464. Its totient is φ = 10590486.

The previous prime is 21180949. The next prime is 21181001. The reversal of 21180974 is 47908112.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21180974.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5295242 + ... + 5295245.

It is an arithmetic number, because the mean of its divisors is an integer number (7942866).

Almost surely, 2^21180974 is an apocalyptic number.

21180974 is a deficient number, since it is larger than the sum of its proper divisors (10590490).

21180974 is a wasteful number, since it uses less digits than its factorization.

21180974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10590489.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 21180974 is about 4602.2792179528. The cubic root of 21180974 is about 276.6826812878.

The spelling of 21180974 in words is "twenty-one million, one hundred eighty thousand, nine hundred seventy-four".