1220786640 has 200 divisors, whose sum is σ = 4424859648. Its totient is φ = 311351040.

The previous prime is 1220786629. The next prime is 1220786653. The reversal of 1220786640 is 466870221.

1220786640 is a `hidden beast` number, since 1 + 2 + 2 + 0 + 7 + 8 + 6 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1220786595 and 1220786604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 144945 + ... + 153135.

Almost surely, 2^1220786640 is an apocalyptic number.

1220786640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220786640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2212429824).

1220786640 is an abundant number, since it is smaller than the sum of its proper divisors (3204073008).

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

1220786640 is a wasteful number, since it uses less digits than its factorization.

1220786640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8239 (or 8224 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 1220786640 is about 34939.7572973826. The cubic root of 1220786640 is about 1068.7593387919.

The spelling of 1220786640 in words is "one billion, two hundred twenty million, seven hundred eighty-six thousand, six hundred forty".