21137117 has 4 divisors (see below), whose sum is σ = 21158880. Its totient is φ = 21115356.

The previous prime is 21137107. The next prime is 21137119. The reversal of 21137117 is 71173112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21137117 - 2⁸ = 21136861 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21137092 and 21137101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21137119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9353 + ... + 11390.

It is an arithmetic number, because the mean of its divisors is an integer number (5289720).

Almost surely, 2^21137117 is an apocalyptic number.

It is an amenable number.

21137117 is a deficient number, since it is larger than the sum of its proper divisors (21763).

21137117 is a wasteful number, since it uses less digits than its factorization.

21137117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21762.

The product of its digits is 294, while the sum is 23.

The square root of 21137117 is about 4597.5120445737. The cubic root of 21137117 is about 276.4915843604.

The spelling of 21137117 in words is "twenty-one million, one hundred thirty-seven thousand, one hundred seventeen".