21457098 has 48 divisors (see below), whose sum is σ = 51158016. Its totient is φ = 6458400.

The previous prime is 21457087. The next prime is 21457133. The reversal of 21457098 is 89075412.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10023 + ... + 11973.

It is an arithmetic number, because the mean of its divisors is an integer number (1065792).

Almost surely, 2^21457098 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21457098, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25579008).

21457098 is an abundant number, since it is smaller than the sum of its proper divisors (29700918).

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

21457098 is a wasteful number, since it uses less digits than its factorization.

21457098 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2019 (or 2016 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21457098 is about 4632.1806959574. The cubic root of 21457098 is about 277.8798110617.

The spelling of 21457098 in words is "twenty-one million, four hundred fifty-seven thousand, ninety-eight".