21242732047 has 4 divisors (see below), whose sum is σ = 21243030136. Its totient is φ = 21242433960.

The previous prime is 21242732033. The next prime is 21242732057. The reversal of 21242732047 is 74023724212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21242732047 - 2⁷ = 21242731919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242732057) 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, 27772 + ... + 207982.

It is an arithmetic number, because the mean of its divisors is an integer number (5310757534).

Almost surely, 2^21242732047 is an apocalyptic number.

21242732047 is a deficient number, since it is larger than the sum of its proper divisors (298089).

21242732047 is a wasteful number, since it uses less digits than its factorization.

21242732047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298088.

The product of its (nonzero) digits is 37632, while the sum is 34.

The spelling of 21242732047 in words is "twenty-one billion, two hundred forty-two million, seven hundred thirty-two thousand, forty-seven".