1861538480 has 20 divisors (see below), whose sum is σ = 4328077152. Its totient is φ = 744615360.

The previous prime is 1861538477. The next prime is 1861538489. The reversal of 1861538480 is 848351681.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (1861538489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11634536 + ... + 11634695.

Almost surely, 2^1861538480 is an apocalyptic number.

1861538480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1861538480 is an abundant number, since it is smaller than the sum of its proper divisors (2466538672).

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

1861538480 is a wasteful number, since it uses less digits than its factorization.

1861538480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23269244 (or 23269238 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 44.

The square root of 1861538480 is about 43145.5499443454. The cubic root of 1861538480 is about 1230.1479276555.

The spelling of 1861538480 in words is "one billion, eight hundred sixty-one million, five hundred thirty-eight thousand, four hundred eighty".