21275139399 has 16 divisors (see below), whose sum is σ = 29066415840. Its totient is φ = 13833827840.

The previous prime is 21275139383. The next prime is 21275139409. The reversal of 21275139399 is 99393157212.

It is a cyclic number.

It is not a de Polignac number, because 21275139399 - 2⁴ = 21275139383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21275139349) 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, 490507 + ... + 532115.

It is an arithmetic number, because the mean of its divisors is an integer number (1816650990).

Almost surely, 2^21275139399 is an apocalyptic number.

21275139399 is a deficient number, since it is larger than the sum of its proper divisors (7791276441).

21275139399 is a wasteful number, since it uses less digits than its factorization.

21275139399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45810.

The product of its digits is 918540, while the sum is 51.

The spelling of 21275139399 in words is "twenty-one billion, two hundred seventy-five million, one hundred thirty-nine thousand, three hundred ninety-nine".