2100155400 has 144 divisors (see below), whose sum is σ = 8060644800. Its totient is φ = 480032640.

The previous prime is 2100155383. The next prime is 2100155411. The reversal of 2100155400 is 45510012.

2100155400 is a `hidden beast` number, since 210 + 0 + 1 + 55 + 400 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 70740 + ... + 95939.

It is an arithmetic number, because the mean of its divisors is an integer number (55976700).

Almost surely, 2^2100155400 is an apocalyptic number.

2100155400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100155400 is an abundant number, since it is smaller than the sum of its proper divisors (5960489400).

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

2100155400 is a wasteful number, since it uses less digits than its factorization.

2100155400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166708 (or 166696 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 2100155400 is about 45827.4524711990. The cubic root of 2100155400 is about 1280.6107518278.

Adding to 2100155400 its reverse (45510012), we get a palindrome (2145665412).

The spelling of 2100155400 in words is "two billion, one hundred million, one hundred fifty-five thousand, four hundred".