21273434745 has 8 divisors (see below), whose sum is σ = 34037495616. Its totient is φ = 11345831856.

The previous prime is 21273434723. The next prime is 21273434747. The reversal of 21273434745 is 54743437212.

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

It is not a de Polignac number, because 21273434745 - 2⁶ = 21273434681 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21273434697 and 21273434706.

It is not an unprimeable number, because it can be changed into a prime (21273434747) 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, 709114477 + ... + 709114506.

It is an arithmetic number, because the mean of its divisors is an integer number (4254686952).

Almost surely, 2^21273434745 is an apocalyptic number.

It is an amenable number.

21273434745 is a deficient number, since it is larger than the sum of its proper divisors (12764060871).

21273434745 is a wasteful number, since it uses less digits than its factorization.

21273434745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1418228991.

The product of its digits is 564480, while the sum is 42.

The spelling of 21273434745 in words is "twenty-one billion, two hundred seventy-three million, four hundred thirty-four thousand, seven hundred forty-five".