21042534709 has 8 divisors (see below), whose sum is σ = 24170686848. Its totient is φ = 17944901520.

The previous prime is 21042534701. The next prime is 21042534727. The reversal of 21042534709 is 90743524012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21042534709 - 2³ = 21042534701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042534701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7628257 + ... + 7631014.

It is an arithmetic number, because the mean of its divisors is an integer number (3021335856).

Almost surely, 2^21042534709 is an apocalyptic number.

It is an amenable number.

21042534709 is a deficient number, since it is larger than the sum of its proper divisors (3128152139).

21042534709 is a wasteful number, since it uses less digits than its factorization.

21042534709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15259475.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 21042534709 in words is "twenty-one billion, forty-two million, five hundred thirty-four thousand, seven hundred nine".