1861613425221 has 32 divisors (see below), whose sum is σ = 2898627724800. Its totient is φ = 1050752508480.

The previous prime is 1861613425219. The next prime is 1861613425271. The reversal of 1861613425221 is 1225243161681.

It is not a de Polignac number, because 1861613425221 - 2¹ = 1861613425219 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861613425271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25124706 + ... + 25198691.

It is an arithmetic number, because the mean of its divisors is an integer number (90582116400).

Almost surely, 2^{1861613425221} is an apocalyptic number.

1861613425221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1861613425221 is a deficient number, since it is larger than the sum of its proper divisors (1037014299579).

1861613425221 is a wasteful number, since it uses less digits than its factorization.

1861613425221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50323489.

The product of its digits is 138240, while the sum is 42.

The spelling of 1861613425221 in words is "one trillion, eight hundred sixty-one billion, six hundred thirteen million, four hundred twenty-five thousand, two hundred twenty-one".