21092945749 has 4 divisors (see below), whose sum is σ = 21259032064. Its totient is φ = 20926859436.

The previous prime is 21092945723. The next prime is 21092945837. The reversal of 21092945749 is 94754929012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21092945749 - 2²⁵ = 21059391317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21092945696 and 21092945705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21092945719) 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, 83042967 + ... + 83043220.

It is an arithmetic number, because the mean of its divisors is an integer number (5314758016).

Almost surely, 2^21092945749 is an apocalyptic number.

It is an amenable number.

21092945749 is a deficient number, since it is larger than the sum of its proper divisors (166086315).

21092945749 is a wasteful number, since it uses less digits than its factorization.

21092945749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166086314.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 21092945749 in words is "twenty-one billion, ninety-two million, nine hundred forty-five thousand, seven hundred forty-nine".