21354670511 has 2 divisors, whose sum is σ = 21354670512. Its totient is φ = 21354670510.

The previous prime is 21354670489. The next prime is 21354670517. The reversal of 21354670511 is 11507645312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21354670511 - 2¹⁸ = 21354408367 is a prime.

It is a super-2 number, since 2×21354670511² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21354670517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677335255 + 10677335256.

It is an arithmetic number, because the mean of its divisors is an integer number (10677335256).

Almost surely, 2^21354670511 is an apocalyptic number.

21354670511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354670511 is an equidigital number, since it uses as much as digits as its factorization.

21354670511 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25200, while the sum is 35.

The spelling of 21354670511 in words is "twenty-one billion, three hundred fifty-four million, six hundred seventy thousand, five hundred eleven".