1845921561 has 16 divisors (see below), whose sum is σ = 2688940800. Its totient is φ = 1117088720.

The previous prime is 1845921559. The next prime is 1845921631. The reversal of 1845921561 is 1651295481.

It is not a de Polignac number, because 1845921561 - 2¹ = 1845921559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1845921541) 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, 18411 + ... + 63488.

It is an arithmetic number, because the mean of its divisors is an integer number (168058800).

Almost surely, 2^1845921561 is an apocalyptic number.

1845921561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1845921561 is a deficient number, since it is larger than the sum of its proper divisors (843019239).

1845921561 is a wasteful number, since it uses less digits than its factorization.

1845921561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82596.

The product of its digits is 86400, while the sum is 42.

The square root of 1845921561 is about 42964.1892859623. The cubic root of 1845921561 is about 1226.6982550923.

The spelling of 1845921561 in words is "one billion, eight hundred forty-five million, nine hundred twenty-one thousand, five hundred sixty-one".