1220372640 has 144 divisors (see below), whose sum is σ = 4345705728. Its totient is φ = 311275008.

The previous prime is 1220372633. The next prime is 1220372651. The reversal of 1220372640 is 462730221.

1220372640 is a `hidden beast` number, since 12 + 2 + 0 + 3 + 7 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14697 + ... + 51543.

It is an arithmetic number, because the mean of its divisors is an integer number (30178512).

Almost surely, 2^1220372640 is an apocalyptic number.

1220372640 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 1220372640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2172852864).

1220372640 is an abundant number, since it is smaller than the sum of its proper divisors (3125333088).

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

1220372640 is a wasteful number, since it uses less digits than its factorization.

1220372640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36891 (or 36880 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 1220372640 is about 34933.8323119580. The cubic root of 1220372640 is about 1068.6385105821.

The spelling of 1220372640 in words is "one billion, two hundred twenty million, three hundred seventy-two thousand, six hundred forty".