221533660225251 has 40 divisors (see below), whose sum is σ = 361441050982704. Its totient is φ = 134105423186880.

The previous prime is 221533660225159. The next prime is 221533660225301. The reversal of 221533660225251 is 152522066335122.

221533660225251 is a `hidden beast` number, since 2 + 2 + 1 + 5 + 3 + 36 + 602 + 2 + 5 + 2 + 5 + 1 = 666.

It is not a de Polignac number, because 221533660225251 - 2¹⁵ = 221533660192483 is a prime.

It is a super-2 number, since 2×221533660225251² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221533660225197 and 221533660225206.

It is not an unprimeable number, because it can be changed into a prime (221533660125251) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 144981396 + ... + 146501441.

Almost surely, 2^{221533660225251} is an apocalyptic number.

221533660225251 is a deficient number, since it is larger than the sum of its proper divisors (139907390757453).

221533660225251 is a wasteful number, since it uses less digits than its factorization.

221533660225251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291483713 (or 291483704 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 45.

The spelling of 221533660225251 in words is "two hundred twenty-one trillion, five hundred thirty-three billion, six hundred sixty million, two hundred twenty-five thousand, two hundred fifty-one".