1220365640 has 32 divisors (see below), whose sum is σ = 2957041080. Its totient is φ = 450596352.

The previous prime is 1220365637. The next prime is 1220365673. The reversal of 1220365640 is 465630221.

It can be written as a sum of positive squares in 4 ways, for example, as 966090724 + 254274916 = 31082^2 + 15946^2 .

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, 1172909 + ... + 1173948.

Almost surely, 2^1220365640 is an apocalyptic number.

1220365640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220365640 is an abundant number, since it is smaller than the sum of its proper divisors (1736675440).

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

1220365640 is a wasteful number, since it uses less digits than its factorization.

1220365640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2346881 (or 2346877 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 1220365640 is about 34933.7321224057. The cubic root of 1220365640 is about 1068.6364673581.

Adding to 1220365640 its reverse (465630221), we get a palindrome (1685995861).

The spelling of 1220365640 in words is "one billion, two hundred twenty million, three hundred sixty-five thousand, six hundred forty".