2861691840 has 672 divisors, whose sum is σ = 12273930240. Its totient is φ = 597196800.

The previous prime is 2861691827. The next prime is 2861691869. The reversal of 2861691840 is 481961682.

2861691840 is a `hidden beast` number, since 28 + 616 + 9 + 1 + 8 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11874120 + ... + 11874360.

Almost surely, 2^2861691840 is an apocalyptic number.

2861691840 is a gapful number since it is divisible by the number (20) 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 2861691840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6136965120).

2861691840 is an abundant number, since it is smaller than the sum of its proper divisors (9412238400).

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

2861691840 is a wasteful number, since it uses less digits than its factorization.

2861691840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 2861691840 is about 53494.7832970655. The cubic root of 2861691840 is about 1419.7360879639.

The spelling of 2861691840 in words is "two billion, eight hundred sixty-one million, six hundred ninety-one thousand, eight hundred forty".