21136757 has 4 divisors (see below), whose sum is σ = 21288960. Its totient is φ = 20984556.

The previous prime is 21136751. The next prime is 21136769. The reversal of 21136757 is 75763112.

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 21136757 - 2⁸ = 21136501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21136751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75893 + ... + 76170.

It is an arithmetic number, because the mean of its divisors is an integer number (5322240).

Almost surely, 2^21136757 is an apocalyptic number.

It is an amenable number.

21136757 is a deficient number, since it is larger than the sum of its proper divisors (152203).

21136757 is a wasteful number, since it uses less digits than its factorization.

21136757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152202.

The product of its digits is 8820, while the sum is 32.

The square root of 21136757 is about 4597.4728927967. The cubic root of 21136757 is about 276.4900146488.

Adding to 21136757 its reverse (75763112), we get a palindrome (96899869).

The spelling of 21136757 in words is "twenty-one million, one hundred thirty-six thousand, seven hundred fifty-seven".