1861400813 has 8 divisors (see below), whose sum is σ = 1907258496. Its totient is φ = 1815660000.

The previous prime is 1861400791. The next prime is 1861400819. The reversal of 1861400813 is 3180041681.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1861400813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1861400813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861400819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3473 + ... + 61113.

It is an arithmetic number, because the mean of its divisors is an integer number (238407312).

Almost surely, 2^1861400813 is an apocalyptic number.

It is an amenable number.

1861400813 is a deficient number, since it is larger than the sum of its proper divisors (45857683).

1861400813 is an equidigital number, since it uses as much as digits as its factorization.

1861400813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58435.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 1861400813 is about 43143.9545359486. The cubic root of 1861400813 is about 1230.1176023893.

The spelling of 1861400813 in words is "one billion, eight hundred sixty-one million, four hundred thousand, eight hundred thirteen".