21690948 has 24 divisors (see below), whose sum is σ = 52245760. Its totient is φ = 6996960.

The previous prime is 21690943. The next prime is 21690959. The reversal of 21690948 is 84909612.

It is not an unprimeable number, because it can be changed into a prime (21690943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28783 + ... + 29526.

Almost surely, 2^21690948 is an apocalyptic number.

It is an amenable number.

21690948 is an abundant number, since it is smaller than the sum of its proper divisors (30554812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21690948 is a wasteful number, since it uses less digits than its factorization.

21690948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58347 (or 58345 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21690948 is about 4657.3541845129. The cubic root of 21690948 is about 278.8856560515.

The spelling of 21690948 in words is "twenty-one million, six hundred ninety thousand, nine hundred forty-eight".