1213515312100 has 144 divisors (see below), whose sum is σ = 3255558519808. Its totient is φ = 382334722560.

The previous prime is 1213515312091. The next prime is 1213515312103. The reversal of 1213515312100 is 12135153121.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (1213515312103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1730302 + ... + 2328298.

Almost surely, 2^{1213515312100} is an apocalyptic number.

1213515312100 is a gapful number since it is divisible by the number (10) 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 1213515312100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1627779259904).

1213515312100 is an abundant number, since it is smaller than the sum of its proper divisors (2042043207708).

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

1213515312100 is a wasteful number, since it uses less digits than its factorization.

1213515312100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598254 (or 598247 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 25.

1213515312100 divided by its reverse (12135153121) gives a square (100 = 10²).

The spelling of 1213515312100 in words is "one trillion, two hundred thirteen billion, five hundred fifteen million, three hundred twelve thousand, one hundred".