21427899047 has 4 divisors (see below), whose sum is σ = 21571710600. Its totient is φ = 21284087496.

The previous prime is 21427899043. The next prime is 21427899071. The reversal of 21427899047 is 74099872412.

It is a happy number.

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 21427899047 - 2² = 21427899043 is a prime.

It is a super-3 number, since 3×21427899047³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21427899047.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21427899043) 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, 71905553 + ... + 71905850.

It is an arithmetic number, because the mean of its divisors is an integer number (5392927650).

Almost surely, 2^21427899047 is an apocalyptic number.

21427899047 is a deficient number, since it is larger than the sum of its proper divisors (143811553).

21427899047 is a wasteful number, since it uses less digits than its factorization.

21427899047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143811552.

The product of its (nonzero) digits is 2032128, while the sum is 53.

The spelling of 21427899047 in words is "twenty-one billion, four hundred twenty-seven million, eight hundred ninety-nine thousand, forty-seven".