1216898820 has 72 divisors (see below), whose sum is σ = 3743288640. Its totient is φ = 319932480.

The previous prime is 1216898807. The next prime is 1216898849. The reversal of 1216898820 is 288986121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34830 + ... + 60389.

It is an arithmetic number, because the mean of its divisors is an integer number (51990120).

Almost surely, 2^1216898820 is an apocalyptic number.

1216898820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216898820 is an abundant number, since it is smaller than the sum of its proper divisors (2526389820).

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

1216898820 is a wasteful number, since it uses less digits than its factorization.

1216898820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95305 (or 95300 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 1216898820 is about 34884.0768833002. The cubic root of 1216898820 is about 1067.6235785759.

The spelling of 1216898820 in words is "one billion, two hundred sixteen million, eight hundred ninety-eight thousand, eight hundred twenty".