21506134044742 has 4 divisors (see below), whose sum is σ = 32259201067116. Its totient is φ = 10753067022370.

The previous prime is 21506134044737. The next prime is 21506134044757. The reversal of 21506134044742 is 24744043160512.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5376533511184 + ... + 5376533511187.

It is an arithmetic number, because the mean of its divisors is an integer number (8064800266779).

Almost surely, 2^{21506134044742} is an apocalyptic number.

21506134044742 is a deficient number, since it is larger than the sum of its proper divisors (10753067022374).

21506134044742 is a wasteful number, since it uses less digits than its factorization.

21506134044742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10753067022373.

The product of its (nonzero) digits is 645120, while the sum is 43.

The spelling of 21506134044742 in words is "twenty-one trillion, five hundred six billion, one hundred thirty-four million, forty-four thousand, seven hundred forty-two".