21974138 has 8 divisors (see below), whose sum is σ = 33099840. Its totient is φ = 10940860.

The previous prime is 21974119. The next prime is 21974179. The reversal of 21974138 is 83147912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21974098 and 21974107.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22508 + ... + 23463.

It is an arithmetic number, because the mean of its divisors is an integer number (4137480).

Almost surely, 2^21974138 is an apocalyptic number.

21974138 is a deficient number, since it is larger than the sum of its proper divisors (11125702).

21974138 is a wasteful number, since it uses less digits than its factorization.

21974138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46212.

The product of its digits is 12096, while the sum is 35.

The square root of 21974138 is about 4687.6580506688. The cubic root of 21974138 is about 280.0940925268.

The spelling of 21974138 in words is "twenty-one million, nine hundred seventy-four thousand, one hundred thirty-eight".