21127102651 has 4 divisors (see below), whose sum is σ = 21136917672. Its totient is φ = 21117287632.

The previous prime is 21127102639. The next prime is 21127102693. The reversal of 21127102651 is 15620172112.

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

It is a cyclic number.

It is not a de Polignac number, because 21127102651 - 2¹³ = 21127094459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21127109651) 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, 4904281 + ... + 4908586.

It is an arithmetic number, because the mean of its divisors is an integer number (5284229418).

Almost surely, 2^21127102651 is an apocalyptic number.

21127102651 is a deficient number, since it is larger than the sum of its proper divisors (9815021).

21127102651 is an equidigital number, since it uses as much as digits as its factorization.

21127102651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9815020.

The product of its (nonzero) digits is 1680, while the sum is 28.

Adding to 21127102651 its reverse (15620172112), we get a palindrome (36747274763).

The spelling of 21127102651 in words is "twenty-one billion, one hundred twenty-seven million, one hundred two thousand, six hundred fifty-one".