21298710 has 16 divisors (see below), whose sum is σ = 51116976. Its totient is φ = 5679648.

The previous prime is 21298691. The next prime is 21298723. The reversal of 21298710 is 1789212.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 709957 = 21298710 / (2 + 1 + 2 + 9 + 8 + 7 + 1 + 0).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354949 + ... + 355008.

It is an arithmetic number, because the mean of its divisors is an integer number (3194811).

Almost surely, 2^21298710 is an apocalyptic number.

21298710 is an abundant number, since it is smaller than the sum of its proper divisors (29818266).

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

21298710 is a wasteful number, since it uses less digits than its factorization.

21298710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709967.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21298710 is about 4615.0525457464. The cubic root of 21298710 is about 277.1943880059.

The spelling of 21298710 in words is "twenty-one million, two hundred ninety-eight thousand, seven hundred ten".