221655636471451 has 96 divisors (see below), whose sum is σ = 279618287542272. Its totient is φ = 171101497754880.

The previous prime is 221655636471413. The next prime is 221655636471461. The reversal of 221655636471451 is 154174636556122.

It is not a de Polignac number, because 221655636471451 - 2¹³ = 221655636463259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221655636471461) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 150683640646 + ... + 150683642116.

It is an arithmetic number, because the mean of its divisors is an integer number (2912690495232).

Almost surely, 2^{221655636471451} is an apocalyptic number.

221655636471451 is a deficient number, since it is larger than the sum of its proper divisors (57962651070821).

221655636471451 is a wasteful number, since it uses less digits than its factorization.

221655636471451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3449 (or 3402 counting only the distinct ones).

The product of its digits is 36288000, while the sum is 58.

The spelling of 221655636471451 in words is "two hundred twenty-one trillion, six hundred fifty-five billion, six hundred thirty-six million, four hundred seventy-one thousand, four hundred fifty-one".