1221532700 has 18 divisors (see below), whose sum is σ = 2650726176. Its totient is φ = 488613040.

The previous prime is 1221532699. The next prime is 1221532717. The reversal of 1221532700 is 72351221.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6107564 + ... + 6107763.

Almost surely, 2^1221532700 is an apocalyptic number.

1221532700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221532700 is an abundant number, since it is smaller than the sum of its proper divisors (1429193476).

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

1221532700 is a wasteful number, since it uses less digits than its factorization.

1221532700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12215341 (or 12215334 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 1221532700 is about 34950.4320431093. The cubic root of 1221532700 is about 1068.9770116135.

Adding to 1221532700 its reverse (72351221), we get a palindrome (1293883921).

The spelling of 1221532700 in words is "one billion, two hundred twenty-one million, five hundred thirty-two thousand, seven hundred".