21890648 has 16 divisors (see below), whose sum is σ = 44202480. Its totient is φ = 10103328.

The previous prime is 21890647. The next prime is 21890651. The reversal of 21890648 is 84609812.

It is a super-3 number, since 3×21890648³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21890647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105140 + ... + 105347.

It is an arithmetic number, because the mean of its divisors is an integer number (2762655).

Almost surely, 2^21890648 is an apocalyptic number.

It is an amenable number.

21890648 is an abundant number, since it is smaller than the sum of its proper divisors (22311832).

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

21890648 is a wasteful number, since it uses less digits than its factorization.

21890648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210506 (or 210502 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21890648 is about 4678.7442759783. The cubic root of 21890648 is about 279.7389062715.

The spelling of 21890648 in words is "twenty-one million, eight hundred ninety thousand, six hundred forty-eight".