16505231377 has 2 divisors, whose sum is σ = 16505231378. Its totient is φ = 16505231376.

The previous prime is 16505231359. The next prime is 16505231381. The reversal of 16505231377 is 77313250561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13060832656 + 3444398721 = 114284^2 + 58689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16505231377 is a prime.

It is a super-2 number, since 2×16505231377² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16505231777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252615688 + 8252615689.

It is an arithmetic number, because the mean of its divisors is an integer number (8252615689).

Almost surely, 2^16505231377 is an apocalyptic number.

It is an amenable number.

16505231377 is a deficient number, since it is larger than the sum of its proper divisors (1).

16505231377 is an equidigital number, since it uses as much as digits as its factorization.

16505231377 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 132300, while the sum is 40.

The spelling of 16505231377 in words is "sixteen billion, five hundred five million, two hundred thirty-one thousand, three hundred seventy-seven".