21347272421 has 16 divisors (see below), whose sum is σ = 22654066176. Its totient is φ = 20082720000.

The previous prime is 21347272411. The next prime is 21347272451. The reversal of 21347272421 is 12427274312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21347272421 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 (21347272411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 327266 + ... + 387036.

It is an arithmetic number, because the mean of its divisors is an integer number (1415879136).

Almost surely, 2^21347272421 is an apocalyptic number.

It is an amenable number.

21347272421 is a deficient number, since it is larger than the sum of its proper divisors (1306793755).

21347272421 is a wasteful number, since it uses less digits than its factorization.

21347272421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60124.

The product of its digits is 37632, while the sum is 35.

The spelling of 21347272421 in words is "twenty-one billion, three hundred forty-seven million, two hundred seventy-two thousand, four hundred twenty-one".