1861725537761 has 4 divisors (see below), whose sum is σ = 1959711092400. Its totient is φ = 1763739983124.

The previous prime is 1861725537751. The next prime is 1861725537797. The reversal of 1861725537761 is 1677355271681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1861725537761 - 2⁶ = 1861725537697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1861725537761.

It is not an unprimeable number, because it can be changed into a prime (1861725537751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48992777291 + ... + 48992777328.

It is an arithmetic number, because the mean of its divisors is an integer number (489927773100).

Almost surely, 2^{1861725537761} is an apocalyptic number.

It is an amenable number.

1861725537761 is a deficient number, since it is larger than the sum of its proper divisors (97985554639).

1861725537761 is an equidigital number, since it uses as much as digits as its factorization.

1861725537761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97985554638.

The product of its digits is 14817600, while the sum is 59.

The spelling of 1861725537761 in words is "one trillion, eight hundred sixty-one billion, seven hundred twenty-five million, five hundred thirty-seven thousand, seven hundred sixty-one".