1881198778624 has 81 divisors (see below), whose sum is σ = 4127980394209. Its totient is φ = 854980628480.

The previous prime is 1881198778573. The next prime is 1881198778633. The reversal of 1881198778624 is 4268778911881.

The square root of 1881198778624 is 1371568.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1834182662400 + 47016116224 = 1354320^2 + 216832^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 241392072 + ... + 241399864.

Almost surely, 2^{1881198778624} is an apocalyptic number.

1881198778624 is the 1371568-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1881198778624

1881198778624 is an abundant number, since it is smaller than the sum of its proper divisors (2246781615585).

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

1881198778624 is an frugal number, since it uses more digits than its factorization.

1881198778624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15624 (or 7806 counting only the distinct ones).

The product of its digits is 86704128, while the sum is 70.

The spelling of 1881198778624 in words is "one trillion, eight hundred eighty-one billion, one hundred ninety-eight million, seven hundred seventy-eight thousand, six hundred twenty-four".