1861613266420 has 48 divisors (see below), whose sum is σ = 4004948859408. Its totient is φ = 726445117440.

The previous prime is 1861613266397. The next prime is 1861613266421. The reversal of 1861613266420 is 246623161681.

It can be written as a sum of positive squares in 8 ways, for example, as 285579084816 + 1576034181604 = 534396^2 + 1255402^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861613266421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19495432 + ... + 19590688.

It is an arithmetic number, because the mean of its divisors is an integer number (83436434571).

Almost surely, 2^{1861613266420} is an apocalyptic number.

1861613266420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1861613266420 is an abundant number, since it is smaller than the sum of its proper divisors (2143335592988).

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

1861613266420 is a wasteful number, since it uses less digits than its factorization.

1861613266420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119140 (or 119138 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 46.

The spelling of 1861613266420 in words is "one trillion, eight hundred sixty-one billion, six hundred thirteen million, two hundred sixty-six thousand, four hundred twenty".