21154714251 has 8 divisors (see below), whose sum is σ = 30770493504. Its totient is φ = 12821038920.

The previous prime is 21154714181. The next prime is 21154714253. The reversal of 21154714251 is 15241745112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21154714251 - 2¹⁰ = 21154713227 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 641051947 = 21154714251 / (2 + 1 + 1 + 5 + 4 + 7 + 1 + 4 + 2 + 5 + 1).

It is not an unprimeable number, because it can be changed into a prime (21154714253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320525941 + ... + 320526006.

It is an arithmetic number, because the mean of its divisors is an integer number (3846311688).

Almost surely, 2^21154714251 is an apocalyptic number.

21154714251 is a deficient number, since it is larger than the sum of its proper divisors (9615779253).

21154714251 is a wasteful number, since it uses less digits than its factorization.

21154714251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641051961.

The product of its digits is 11200, while the sum is 33.

The spelling of 21154714251 in words is "twenty-one billion, one hundred fifty-four million, seven hundred fourteen thousand, two hundred fifty-one".