1215816380 has 12 divisors (see below), whose sum is σ = 2553214440. Its totient is φ = 486326544.

The previous prime is 1215816379. The next prime is 1215816383. The reversal of 1215816380 is 836185121.

It is a self number, because there is not a number n which added to its sum of digits gives 1215816380.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215816383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30395390 + ... + 30395429.

It is an arithmetic number, because the mean of its divisors is an integer number (212767870).

Almost surely, 2^1215816380 is an apocalyptic number.

1215816380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1215816380 is an abundant number, since it is smaller than the sum of its proper divisors (1337398060).

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

1215816380 is a wasteful number, since it uses less digits than its factorization.

1215816380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60790828 (or 60790826 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 1215816380 is about 34868.5586166105. The cubic root of 1215816380 is about 1067.3069317941.

The spelling of 1215816380 in words is "one billion, two hundred fifteen million, eight hundred sixteen thousand, three hundred eighty".