1221793680 has 40 divisors (see below), whose sum is σ = 3787561152. Its totient is φ = 325811584.

The previous prime is 1221793673. The next prime is 1221793711. The reversal of 1221793680 is 863971221.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2545164 + ... + 2545643.

Almost surely, 2^1221793680 is an apocalyptic number.

1221793680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221793680 is an abundant number, since it is smaller than the sum of its proper divisors (2565767472).

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

1221793680 is a wasteful number, since it uses less digits than its factorization.

1221793680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5090823 (or 5090817 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 1221793680 is about 34954.1654170143. The cubic root of 1221793680 is about 1069.0531350374.

The spelling of 1221793680 in words is "one billion, two hundred twenty-one million, seven hundred ninety-three thousand, six hundred eighty".