1221511618804 has 12 divisors (see below), whose sum is σ = 2137808342628. Its totient is φ = 610709235200.

The previous prime is 1221511618771. The next prime is 1221511618813. The reversal of 1221511618804 is 4088161151221.

It can be written as a sum of positive squares in 2 ways, for example, as 162773516304 + 1058738102500 = 403452^2 + 1028950^2 .

It is a congruent number.

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, 11584507 + ... + 11689474.

It is an arithmetic number, because the mean of its divisors is an integer number (178150695219).

Almost surely, 2^{1221511618804} is an apocalyptic number.

It is an amenable number.

1221511618804 is a deficient number, since it is larger than the sum of its proper divisors (916296723824).

1221511618804 is a wasteful number, since it uses less digits than its factorization.

1221511618804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23287106 (or 23287104 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 40.

The spelling of 1221511618804 in words is "one trillion, two hundred twenty-one billion, five hundred eleven million, six hundred eighteen thousand, eight hundred four".