1220745840 has 40 divisors (see below), whose sum is σ = 3784312848. Its totient is φ = 325532160.

The previous prime is 1220745833. The next prime is 1220745853. The reversal of 1220745840 is 485470221.

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

It is a congruent number.

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, 2542981 + ... + 2543460.

Almost surely, 2^1220745840 is an apocalyptic number.

1220745840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220745840 is an abundant number, since it is smaller than the sum of its proper divisors (2563567008).

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

1220745840 is a wasteful number, since it uses less digits than its factorization.

1220745840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5086457 (or 5086451 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 33.

The square root of 1220745840 is about 34939.1734304062. The cubic root of 1220745840 is about 1068.7474322978.

The spelling of 1220745840 in words is "one billion, two hundred twenty million, seven hundred forty-five thousand, eight hundred forty".