21158006 has 16 divisors (see below), whose sum is σ = 32848416. Its totient is φ = 10213056.

The previous prime is 21158003. The next prime is 21158041. The reversal of 21158006 is 60085112.

It is a super-2 number, since 2×21158006² = 895322435792072, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158003) 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, 9095 + ... + 11181.

It is an arithmetic number, because the mean of its divisors is an integer number (2053026).

Almost surely, 2^21158006 is an apocalyptic number.

21158006 is a deficient number, since it is larger than the sum of its proper divisors (11690410).

21158006 is a wasteful number, since it uses less digits than its factorization.

21158006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2263.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 21158006 is about 4599.7832557633. The cubic root of 21158006 is about 276.5826363731.

The spelling of 21158006 in words is "twenty-one million, one hundred fifty-eight thousand, six".