1221457800 has 48 divisors (see below), whose sum is σ = 3786521040. Its totient is φ = 325721920.

The previous prime is 1221457799. The next prime is 1221457813. The reversal of 1221457800 is 87541221.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1017282 + ... + 1018481.

It is an arithmetic number, because the mean of its divisors is an integer number (78885855).

Almost surely, 2^1221457800 is an apocalyptic number.

1221457800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221457800 is an abundant number, since it is smaller than the sum of its proper divisors (2565063240).

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

1221457800 is a wasteful number, since it uses less digits than its factorization.

1221457800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2035782 (or 2035773 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 1221457800 is about 34949.3605091710. The cubic root of 1221457800 is about 1068.9551625559.

The spelling of 1221457800 in words is "one billion, two hundred twenty-one million, four hundred fifty-seven thousand, eight hundred".