21042534749 has 8 divisors (see below), whose sum is σ = 21205532160. Its totient is φ = 20880088000.

The previous prime is 21042534727. The next prime is 21042534767. The reversal of 21042534749 is 94743524012.

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

It is a cyclic number.

It is not a de Polignac number, because 21042534749 - 2³² = 16747567453 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 (21042524749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60779 + ... + 213960.

It is an arithmetic number, because the mean of its divisors is an integer number (2650691520).

Almost surely, 2^21042534749 is an apocalyptic number.

It is an amenable number.

21042534749 is a deficient number, since it is larger than the sum of its proper divisors (162997411).

21042534749 is a wasteful number, since it uses less digits than its factorization.

21042534749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275331.

The product of its (nonzero) digits is 241920, while the sum is 41.

The spelling of 21042534749 in words is "twenty-one billion, forty-two million, five hundred thirty-four thousand, seven hundred forty-nine".