1221620116 has 24 divisors (see below), whose sum is σ = 2160053280. Its totient is φ = 604476000.

The previous prime is 1221620111. The next prime is 1221620117. The reversal of 1221620116 is 6110261221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221620111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 631671 + ... + 633601.

It is an arithmetic number, because the mean of its divisors is an integer number (90002220).

Almost surely, 2^1221620116 is an apocalyptic number.

It is an amenable number.

1221620116 is a deficient number, since it is larger than the sum of its proper divisors (938433164).

1221620116 is a wasteful number, since it uses less digits than its factorization.

1221620116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495 (or 3493 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 1221620116 is about 34951.6825918295. The cubic root of 1221620116 is about 1069.0025105803.

Adding to 1221620116 its reverse (6110261221), we get a palindrome (7331881337).

The spelling of 1221620116 in words is "one billion, two hundred twenty-one million, six hundred twenty thousand, one hundred sixteen".