21372774728267 has 2 divisors, whose sum is σ = 21372774728268. Its totient is φ = 21372774728266.

The previous prime is 21372774728191. The next prime is 21372774728311. The reversal of 21372774728267 is 76282747727312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21372774728267 - 2¹⁶ = 21372774662731 is a prime.

It is not a weakly prime, because it can be changed into another prime (21372774758267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10686387364133 + 10686387364134.

It is an arithmetic number, because the mean of its divisors is an integer number (10686387364134).

Almost surely, 2^{21372774728267} is an apocalyptic number.

21372774728267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21372774728267 is an equidigital number, since it uses as much as digits as its factorization.

21372774728267 is an evil number, because the sum of its binary digits is even.

The product of its digits is 154893312, while the sum is 65.

The spelling of 21372774728267 in words is "twenty-one trillion, three hundred seventy-two billion, seven hundred seventy-four million, seven hundred twenty-eight thousand, two hundred sixty-seven".