1861621823552 has 14 divisors (see below), whose sum is σ = 3694155806238. Its totient is φ = 930810911744.

The previous prime is 1861621823527. The next prime is 1861621823557. The reversal of 1861621823552 is 2553281261681.

It can be written as a sum of positive squares in only one way, i.e., 1064644257856 + 796977565696 = 1031816^2 + 892736^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1861621823552.

It is not an unprimeable number, because it can be changed into a prime (1861621823557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14543920433 + ... + 14543920560.

Almost surely, 2^{1861621823552} is an apocalyptic number.

It is an amenable number.

1861621823552 is a deficient number, since it is larger than the sum of its proper divisors (1832533982686).

1861621823552 is an equidigital number, since it uses as much as digits as its factorization.

1861621823552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29087841005 (or 29087840995 counting only the distinct ones).

The product of its digits is 1382400, while the sum is 50.

The spelling of 1861621823552 in words is "one trillion, eight hundred sixty-one billion, six hundred twenty-one million, eight hundred twenty-three thousand, five hundred fifty-two".