221534055631477 has 2 divisors, whose sum is σ = 221534055631478. Its totient is φ = 221534055631476.

The previous prime is 221534055631391. The next prime is 221534055631489. The reversal of 221534055631477 is 774136550435122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182068848037521 + 39465207593956 = 13493289^2 + 6282134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221534055631477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221534055638477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110767027815738 + 110767027815739.

It is an arithmetic number, because the mean of its divisors is an integer number (110767027815739).

Almost surely, 2^{221534055631477} is an apocalyptic number.

It is an amenable number.

221534055631477 is a deficient number, since it is larger than the sum of its proper divisors (1).

221534055631477 is an equidigital number, since it uses as much as digits as its factorization.

221534055631477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168000, while the sum is 55.

The spelling of 221534055631477 in words is "two hundred twenty-one trillion, five hundred thirty-four billion, fifty-five million, six hundred thirty-one thousand, four hundred seventy-seven".