1221010320 has 40 divisors (see below), whose sum is σ = 3785132736. Its totient is φ = 325602688.

The previous prime is 1221010309. The next prime is 1221010339. The reversal of 1221010320 is 230101221.

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

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1221010296 and 1221010305.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2543532 + ... + 2544011.

Almost surely, 2^1221010320 is an apocalyptic number.

1221010320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221010320 is an abundant number, since it is smaller than the sum of its proper divisors (2564122416).

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

1221010320 is a wasteful number, since it uses less digits than its factorization.

1221010320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5087559 (or 5087553 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1221010320 is about 34942.9580888625. The cubic root of 1221010320 is about 1068.8246096814.

Adding to 1221010320 its reverse (230101221), we get a palindrome (1451111541).

Subtracting from 1221010320 its reverse (230101221), we obtain a palindrome (990909099).

The spelling of 1221010320 in words is "one billion, two hundred twenty-one million, ten thousand, three hundred twenty".