21489500 has 24 divisors (see below), whose sum is σ = 46934160. Its totient is φ = 8595600.

The previous prime is 21489497. The next prime is 21489529. The reversal of 21489500 is 598412.

It is a super-2 number, since 2×21489500² = 923597220500000, which contains 22 as substring.

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, 20990 + ... + 21989.

It is an arithmetic number, because the mean of its divisors is an integer number (1955590).

Almost surely, 2^21489500 is an apocalyptic number.

21489500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21489500 is an abundant number, since it is smaller than the sum of its proper divisors (25444660).

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

21489500 is a wasteful number, since it uses less digits than its factorization.

21489500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42998 (or 42986 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21489500 is about 4635.6768653563. The cubic root of 21489500 is about 278.0196145779.

The spelling of 21489500 in words is "twenty-one million, four hundred eighty-nine thousand, five hundred".