21158045 has 16 divisors (see below), whose sum is σ = 26635392. Its totient is φ = 16104000.

The previous prime is 21158041. The next prime is 21158051. The reversal of 21158045 is 54085112.

It is not a de Polignac number, because 21158045 - 2² = 21158041 is a prime.

It is a super-3 number, since 3×21158045³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28499 + ... + 29231.

It is an arithmetic number, because the mean of its divisors is an integer number (1664712).

Almost surely, 2^21158045 is an apocalyptic number.

It is an amenable number.

21158045 is a deficient number, since it is larger than the sum of its proper divisors (5477347).

21158045 is a wasteful number, since it uses less digits than its factorization.

21158045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 21158045 is about 4599.7874950915. The cubic root of 21158045 is about 276.5828063122.

The spelling of 21158045 in words is "twenty-one million, one hundred fifty-eight thousand, forty-five".