1221862320 has 560 divisors, whose sum is σ = 5054801472. Its totient is φ = 268738560.

The previous prime is 1221862319. The next prime is 1221862321. The reversal of 1221862320 is 232681221.

1221862320 is a `hidden beast` number, since 1 + 2 + 2 + 18 + 623 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (1221862319) and next prime (1221862321).

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1221862321) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 16737804 + ... + 16737876.

Almost surely, 2^1221862320 is an apocalyptic number.

1221862320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221862320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527400736).

1221862320 is an abundant number, since it is smaller than the sum of its proper divisors (3832939152).

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

1221862320 is an equidigital number, since it uses as much as digits as its factorization.

1221862320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1221862320 is about 34955.1472604536. The cubic root of 1221862320 is about 1069.0731543566.

The spelling of 1221862320 in words is "one billion, two hundred twenty-one million, eight hundred sixty-two thousand, three hundred twenty".