815851400 has 192 divisors, whose sum is σ = 2437344000. Its totient is φ = 246850560.

The previous prime is 815851381. The next prime is 815851433. The reversal of 815851400 is 4158518.

It is a super-2 number, since 2×815851400² = 1331227013763920000, which contains 22 as substring.

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, 417626 + ... + 419574.

It is an arithmetic number, because the mean of its divisors is an integer number (12694500).

Almost surely, 2^815851400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815851400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1218672000).

815851400 is an abundant number, since it is smaller than the sum of its proper divisors (1621492600).

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

815851400 is a wasteful number, since it uses less digits than its factorization.

815851400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2008 (or 1999 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 32.

The square root of 815851400 is about 28563.1125754880. The cubic root of 815851400 is about 934.4090177136.

The spelling of 815851400 in words is "eight hundred fifteen million, eight hundred fifty-one thousand, four hundred".