21195280 has 40 divisors (see below), whose sum is σ = 49496832. Its totient is φ = 8440704.

The previous prime is 21195257. The next prime is 21195299. The reversal of 21195280 is 8259112.

It is a tau number, because it is divible by the number of its divisors (40).

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, 24129 + ... + 24991.

Almost surely, 2^21195280 is an apocalyptic number.

21195280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21195280 is an abundant number, since it is smaller than the sum of its proper divisors (28301552).

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

21195280 is a wasteful number, since it uses less digits than its factorization.

21195280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1183 (or 1177 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21195280 is about 4603.8331855097. The cubic root of 21195280 is about 276.7449593747.

The spelling of 21195280 in words is "twenty-one million, one hundred ninety-five thousand, two hundred eighty".