2861609400 has 432 divisors, whose sum is σ = 10885352400. Its totient is φ = 672122880.

The previous prime is 2861609389. The next prime is 2861609407. The reversal of 2861609400 is 49061682.

2861609400 is a `hidden beast` number, since 2 + 8 + 6 + 1 + 609 + 40 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2861609407) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 6996396 + ... + 6996804.

It is an arithmetic number, because the mean of its divisors is an integer number (25197575).

Almost surely, 2^2861609400 is an apocalyptic number.

2861609400 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 2861609400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5442676200).

2861609400 is an abundant number, since it is smaller than the sum of its proper divisors (8023743000).

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

2861609400 is a wasteful number, since it uses less digits than its factorization.

2861609400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 2861609400 is about 53494.0127490918. The cubic root of 2861609400 is about 1419.7224545175.

The spelling of 2861609400 in words is "two billion, eight hundred sixty-one million, six hundred nine thousand, four hundred".