21398058 has 48 divisors (see below), whose sum is σ = 51363936. Its totient is φ = 6383520.

The previous prime is 21398033. The next prime is 21398063. The reversal of 21398058 is 85089312.

It is a super-3 number, since 3×21398058³ (a number of 23 digits) contains 333 as substring.

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, 12460 + ... + 14072.

It is an arithmetic number, because the mean of its divisors is an integer number (1070082).

Almost surely, 2^21398058 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21398058, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25681968).

21398058 is an abundant number, since it is smaller than the sum of its proper divisors (29965878).

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

21398058 is a wasteful number, since it uses less digits than its factorization.

21398058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 21398058 is about 4625.8034977720. The cubic root of 21398058 is about 277.6247114152.

The spelling of 21398058 in words is "twenty-one million, three hundred ninety-eight thousand, fifty-eight".