21086748 has 18 divisors (see below), whose sum is σ = 53302704. Its totient is φ = 7028904.

The previous prime is 21086743. The next prime is 21086753. The reversal of 21086748 is 84768012.

It is an interprime number because it is at equal distance from previous prime (21086743) and next prime (21086753).

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 585743 = 21086748 / (2 + 1 + 0 + 8 + 6 + 7 + 4 + 8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086743) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 292836 + ... + 292907.

Almost surely, 2^21086748 is an apocalyptic number.

It is an amenable number.

21086748 is an abundant number, since it is smaller than the sum of its proper divisors (32215956).

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

21086748 is a wasteful number, since it uses less digits than its factorization.

21086748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585753 (or 585748 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21086748 is about 4592.0309232408. The cubic root of 21086748 is about 276.2717864652.

The spelling of 21086748 in words is "twenty-one million, eighty-six thousand, seven hundred forty-eight".