221681318458 has 8 divisors (see below), whose sum is σ = 338795977428. Its totient is φ = 108749325984.

The previous prime is 221681318429. The next prime is 221681318491. The reversal of 221681318458 is 854813186122.

It can be written as a sum of positive squares in 2 ways, for example, as 218942575569 + 2738742889 = 467913^2 + 52333^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×221681318458² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1045666491 + ... + 1045666702.

Almost surely, 2^221681318458 is an apocalyptic number.

221681318458 is a deficient number, since it is larger than the sum of its proper divisors (117114658970).

221681318458 is a wasteful number, since it uses less digits than its factorization.

221681318458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091333248.

The product of its digits is 737280, while the sum is 49.

The spelling of 221681318458 in words is "two hundred twenty-one billion, six hundred eighty-one million, three hundred eighteen thousand, four hundred fifty-eight".