21521058 has 16 divisors (see below), whose sum is σ = 46353216. Its totient is φ = 6621840.

The previous prime is 21521051. The next prime is 21521083. The reversal of 21521058 is 85012512.

It is not an unprimeable number, because it can be changed into a prime (21521051) 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, 137878 + ... + 138033.

It is an arithmetic number, because the mean of its divisors is an integer number (2897076).

Almost surely, 2^21521058 is an apocalyptic number.

21521058 is an abundant number, since it is smaller than the sum of its proper divisors (24832158).

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

21521058 is a wasteful number, since it uses less digits than its factorization.

21521058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275929.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 21521058 is about 4639.0794345430. The cubic root of 21521058 is about 278.1556415005.

The spelling of 21521058 in words is "twenty-one million, five hundred twenty-one thousand, fifty-eight".