21890057 has 8 divisors (see below), whose sum is σ = 25070976. Its totient is φ = 18722592.

The previous prime is 21890047. The next prime is 21890083. The reversal of 21890057 is 75009812.

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

It is not a de Polignac number, because 21890057 - 2⁶ = 21889993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21890047) 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, 413 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (3133872).

Almost surely, 2^21890057 is an apocalyptic number.

It is an amenable number.

21890057 is a deficient number, since it is larger than the sum of its proper divisors (3180919).

21890057 is an equidigital number, since it uses as much as digits as its factorization.

21890057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6727.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 21890057 is about 4678.6811175800. The cubic root of 21890057 is about 279.7363888010.

Adding to 21890057 its reverse (75009812), we get a palindrome (96899869).

The spelling of 21890057 in words is "twenty-one million, eight hundred ninety thousand, fifty-seven".