1861645474441 has 4 divisors (see below), whose sum is σ = 1876304100352. Its totient is φ = 1846986848532.

The previous prime is 1861645474417. The next prime is 1861645474463. The reversal of 1861645474441 is 1444745461681.

It is a happy number.

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 1861645474441 - 2¹⁹ = 1861644950153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1861645474471) 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, 7329312765 + ... + 7329313018.

It is an arithmetic number, because the mean of its divisors is an integer number (469076025088).

Almost surely, 2^{1861645474441} is an apocalyptic number.

It is an amenable number.

1861645474441 is a deficient number, since it is larger than the sum of its proper divisors (14658625911).

1861645474441 is a wasteful number, since it uses less digits than its factorization.

1861645474441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14658625910.

The product of its digits is 10321920, while the sum is 55.

The spelling of 1861645474441 in words is "one trillion, eight hundred sixty-one billion, six hundred forty-five million, four hundred seventy-four thousand, four hundred forty-one".