21919774 has 4 divisors (see below), whose sum is σ = 32879664. Its totient is φ = 10959886.

The previous prime is 21919771. The next prime is 21919811. The reversal of 21919774 is 47791912.

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

It is a super-2 number, since 2×21919774² = 960952984422152, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21919771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5479942 + ... + 5479945.

It is an arithmetic number, because the mean of its divisors is an integer number (8219916).

Almost surely, 2^21919774 is an apocalyptic number.

21919774 is a deficient number, since it is larger than the sum of its proper divisors (10959890).

21919774 is a wasteful number, since it uses less digits than its factorization.

21919774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10959889.

The product of its digits is 31752, while the sum is 40.

The square root of 21919774 is about 4681.8558286218. The cubic root of 21919774 is about 279.8629175920.

The spelling of 21919774 in words is "twenty-one million, nine hundred nineteen thousand, seven hundred seventy-four".