21990273 has 8 divisors (see below), whose sum is σ = 29401728. Its totient is φ = 14619504.

The previous prime is 21990259. The next prime is 21990337. The reversal of 21990273 is 37209912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21990273 - 2⁴ = 21990257 is a prime.

It is a super-2 number, since 2×21990273² = 967144213229058, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21990373) 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, 8886 + ... + 11087.

It is an arithmetic number, because the mean of its divisors is an integer number (3675216).

Almost surely, 2^21990273 is an apocalyptic number.

It is an amenable number.

21990273 is a deficient number, since it is larger than the sum of its proper divisors (7411455).

21990273 is a wasteful number, since it uses less digits than its factorization.

21990273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20343.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 21990273 is about 4689.3787435011. The cubic root of 21990273 is about 280.1626308619.

The spelling of 21990273 in words is "twenty-one million, nine hundred ninety thousand, two hundred seventy-three".