18277847521 has 2 divisors, whose sum is σ = 18277847522. Its totient is φ = 18277847520.

The previous prime is 18277847479. The next prime is 18277847617. The reversal of 18277847521 is 12574877281.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15119407521 + 3158440000 = 122961^2 + 56200^2 .

It is a cyclic number.

It is not a de Polignac number, because 18277847521 - 2²³ = 18269458913 is a prime.

It is not a weakly prime, because it can be changed into another prime (18277547521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9138923760 + 9138923761.

It is an arithmetic number, because the mean of its divisors is an integer number (9138923761).

Almost surely, 2^18277847521 is an apocalyptic number.

It is an amenable number.

18277847521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18277847521 is an equidigital number, since it uses as much as digits as its factorization.

18277847521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1756160, while the sum is 52.

The spelling of 18277847521 in words is "eighteen billion, two hundred seventy-seven million, eight hundred forty-seven thousand, five hundred twenty-one".