221992356877 has 2 divisors, whose sum is σ = 221992356878. Its totient is φ = 221992356876.

The previous prime is 221992356851. The next prime is 221992356881. The reversal of 221992356877 is 778653299122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 143378851716 + 78613505161 = 378654^2 + 280381^2 .

It is a cyclic number.

It is not a de Polignac number, because 221992356877 - 2¹⁵ = 221992324109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221992356977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110996178438 + 110996178439.

It is an arithmetic number, because the mean of its divisors is an integer number (110996178439).

Almost surely, 2^221992356877 is an apocalyptic number.

It is an amenable number.

221992356877 is a deficient number, since it is larger than the sum of its proper divisors (1).

221992356877 is an equidigital number, since it uses as much as digits as its factorization.

221992356877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 61.

The spelling of 221992356877 in words is "two hundred twenty-one billion, nine hundred ninety-two million, three hundred fifty-six thousand, eight hundred seventy-seven".