21269054731 has 4 divisors (see below), whose sum is σ = 21475550512. Its totient is φ = 21062558952.

The previous prime is 21269054711. The next prime is 21269054743. The reversal of 21269054731 is 13745096212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21269054731 is a prime.

It is a super-2 number, since 2×21269054731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21269054711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103247736 + ... + 103247941.

It is an arithmetic number, because the mean of its divisors is an integer number (5368887628).

Almost surely, 2^21269054731 is an apocalyptic number.

21269054731 is a deficient number, since it is larger than the sum of its proper divisors (206495781).

21269054731 is a wasteful number, since it uses less digits than its factorization.

21269054731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206495780.

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 21269054731 in words is "twenty-one billion, two hundred sixty-nine million, fifty-four thousand, seven hundred thirty-one".