1861172460 has 144 divisors (see below), whose sum is σ = 6467924736. Its totient is φ = 424365696.

The previous prime is 1861172437. The next prime is 1861172471. The reversal of 1861172460 is 642711681.

It is a happy number.

1861172460 is a `hidden beast` number, since 1 + 86 + 117 + 2 + 460 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 586839 + ... + 590001.

It is an arithmetic number, because the mean of its divisors is an integer number (44916144).

Almost surely, 2^1861172460 is an apocalyptic number.

1861172460 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1861172460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3233962368).

1861172460 is an abundant number, since it is smaller than the sum of its proper divisors (4606752276).

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

1861172460 is a wasteful number, since it uses less digits than its factorization.

1861172460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3652 (or 3647 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1861172460 is about 43141.3080469288. The cubic root of 1861172460 is about 1230.0672975275.

The spelling of 1861172460 in words is "one billion, eight hundred sixty-one million, one hundred seventy-two thousand, four hundred sixty".