1221897160 has 32 divisors (see below), whose sum is σ = 2999203200. Its totient is φ = 444326080.

The previous prime is 1221897119. The next prime is 1221897179. The reversal of 1221897160 is 617981221.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1388080 + ... + 1388959.

It is an arithmetic number, because the mean of its divisors is an integer number (93725100).

Almost surely, 2^1221897160 is an apocalyptic number.

1221897160 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221897160 is an abundant number, since it is smaller than the sum of its proper divisors (1777306040).

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

1221897160 is a wasteful number, since it uses less digits than its factorization.

1221897160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2777061 (or 2777057 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 1221897160 is about 34955.6456098296. The cubic root of 1221897160 is about 1069.0833153909.

The spelling of 1221897160 in words is "one billion, two hundred twenty-one million, eight hundred ninety-seven thousand, one hundred sixty".