21923474 has 4 divisors (see below), whose sum is σ = 32885214. Its totient is φ = 10961736.

The previous prime is 21923453. The next prime is 21923509. The reversal of 21923474 is 47432912.

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

It can be written as a sum of positive squares in only one way, i.e., 21557449 + 366025 = 4643^2 + 605^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21923474.

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, 5480867 + ... + 5480870.

Almost surely, 2^21923474 is an apocalyptic number.

21923474 is a deficient number, since it is larger than the sum of its proper divisors (10961740).

21923474 is a wasteful number, since it uses less digits than its factorization.

21923474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10961739.

The product of its digits is 12096, while the sum is 32.

The square root of 21923474 is about 4682.2509544022. The cubic root of 21923474 is about 279.8786634134.

The spelling of 21923474 in words is "twenty-one million, nine hundred twenty-three thousand, four hundred seventy-four".