21909068 has 6 divisors (see below), whose sum is σ = 38340876. Its totient is φ = 10954532.

The previous prime is 21909029. The next prime is 21909077. The reversal of 21909068 is 86090912.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2738630 + ... + 2738637.

It is an arithmetic number, because the mean of its divisors is an integer number (6390146).

Almost surely, 2^21909068 is an apocalyptic number.

It is an amenable number.

21909068 is a deficient number, since it is larger than the sum of its proper divisors (16431808).

21909068 is a wasteful number, since it uses less digits than its factorization.

21909068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5477271 (or 5477269 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 21909068 is about 4680.7123389501. The cubic root of 21909068 is about 279.8173468617.

The spelling of 21909068 in words is "twenty-one million, nine hundred nine thousand, sixty-eight".