21519922 has 4 divisors (see below), whose sum is σ = 32279886. Its totient is φ = 10759960.

The previous prime is 21519919. The next prime is 21519923. The reversal of 21519922 is 22991512.

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., 20985561 + 534361 = 4581^2 + 731^2 .

It is not an unprimeable number, because it can be changed into a prime (21519923) by changing a digit.

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, 5379979 + ... + 5379982.

Almost surely, 2^21519922 is an apocalyptic number.

21519922 is a deficient number, since it is larger than the sum of its proper divisors (10759964).

21519922 is a wasteful number, since it uses less digits than its factorization.

21519922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10759963.

The product of its digits is 3240, while the sum is 31.

The square root of 21519922 is about 4638.9569948427. The cubic root of 21519922 is about 278.1507472187.

The spelling of 21519922 in words is "twenty-one million, five hundred nineteen thousand, nine hundred twenty-two".