21498740 has 24 divisors (see below), whose sum is σ = 46109952. Its totient is φ = 8416160.

The previous prime is 21498733. The next prime is 21498793. The reversal of 21498740 is 4789412.

It is a self number, because there is not a number n which added to its sum of digits gives 21498740.

It is a congruent number.

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, 10496 + ... + 12375.

It is an arithmetic number, because the mean of its divisors is an integer number (1921248).

Almost surely, 2^21498740 is an apocalyptic number.

21498740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21498740 is an abundant number, since it is smaller than the sum of its proper divisors (24611212).

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

21498740 is a wasteful number, since it uses less digits than its factorization.

21498740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22927 (or 22925 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 21498740 is about 4636.6733764629. The cubic root of 21498740 is about 278.0594562547.

The spelling of 21498740 in words is "twenty-one million, four hundred ninety-eight thousand, seven hundred forty".