21275471949 has 8 divisors (see below), whose sum is σ = 28415135232. Its totient is φ = 14159728320.

The previous prime is 21275471897. The next prime is 21275471963. The reversal of 21275471949 is 94917457212.

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

It is not a de Polignac number, because 21275471949 - 2¹⁵ = 21275439181 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21275471989) 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, 5977837 + ... + 5981394.

It is an arithmetic number, because the mean of its divisors is an integer number (3551891904).

Almost surely, 2^21275471949 is an apocalyptic number.

It is an amenable number.

21275471949 is a deficient number, since it is larger than the sum of its proper divisors (7139663283).

21275471949 is a wasteful number, since it uses less digits than its factorization.

21275471949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11959827.

The product of its digits is 1270080, while the sum is 51.

The spelling of 21275471949 in words is "twenty-one billion, two hundred seventy-five million, four hundred seventy-one thousand, nine hundred forty-nine".