1611221872 has 40 divisors (see below), whose sum is σ = 3367249760. Its totient is φ = 742452480.

The previous prime is 1611221861. The next prime is 1611221879. The reversal of 1611221872 is 2781221161.

It is a super-2 number, since 2×1611221872² = 5192071841622368768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611221879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131629 + ... + 143347.

It is an arithmetic number, because the mean of its divisors is an integer number (84181244).

Almost surely, 2^1611221872 is an apocalyptic number.

It is an amenable number.

1611221872 is an abundant number, since it is smaller than the sum of its proper divisors (1756027888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1611221872 is a wasteful number, since it uses less digits than its factorization.

1611221872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12401 (or 12395 counting only the distinct ones).

The product of its digits is 2688, while the sum is 31.

The square root of 1611221872 is about 40140.0283009367. The cubic root of 1611221872 is about 1172.3351400544.

The spelling of 1611221872 in words is "one billion, six hundred eleven million, two hundred twenty-one thousand, eight hundred seventy-two".