21954090 has 16 divisors (see below), whose sum is σ = 52689888. Its totient is φ = 5854416.

The previous prime is 21954059. The next prime is 21954103. The reversal of 21954090 is 9045912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 731803 = 21954090 / (2 + 1 + 9 + 5 + 4 + 0 + 9 + 0).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365872 + ... + 365931.

It is an arithmetic number, because the mean of its divisors is an integer number (3293118).

Almost surely, 2^21954090 is an apocalyptic number.

21954090 is an abundant number, since it is smaller than the sum of its proper divisors (30735798).

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

21954090 is a wasteful number, since it uses less digits than its factorization.

21954090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731813.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 21954090 is about 4685.5191814782. The cubic root of 21954090 is about 280.0088857724.

The spelling of 21954090 in words is "twenty-one million, nine hundred fifty-four thousand, ninety".