21246122691 has 20 divisors (see below), whose sum is σ = 33604980552. Its totient is φ = 13330899648.

The previous prime is 21246122669. The next prime is 21246122719. The reversal of 21246122691 is 19622164212.

It is a happy number.

21246122691 is a `hidden beast` number, since 2 + 12 + 4 + 612 + 26 + 9 + 1 = 666.

It is not a de Polignac number, because 21246122691 - 2⁹ = 21246122179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21246120691) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7713265 + ... + 7716018.

Almost surely, 2^21246122691 is an apocalyptic number.

21246122691 is a deficient number, since it is larger than the sum of its proper divisors (12358857861).

21246122691 is a wasteful number, since it uses less digits than its factorization.

21246122691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15429312 (or 15429303 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The spelling of 21246122691 in words is "twenty-one billion, two hundred forty-six million, one hundred twenty-two thousand, six hundred ninety-one".