21308292 has 24 divisors (see below), whose sum is σ = 55244000. Its totient is φ = 7102728.

The previous prime is 21308219. The next prime is 21308299. The reversal of 21308292 is 29280312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21308299) 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, 98542 + ... + 98757.

Almost surely, 2^21308292 is an apocalyptic number.

It is an amenable number.

21308292 is an abundant number, since it is smaller than the sum of its proper divisors (33935708).

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

21308292 is a wasteful number, since it uses less digits than its factorization.

21308292 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197312 (or 197304 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21308292 is about 4616.0905537045. The cubic root of 21308292 is about 277.2359504356.

The spelling of 21308292 in words is "twenty-one million, three hundred eight thousand, two hundred ninety-two".