1220405940 has 240 divisors, whose sum is σ = 4159596672. Its totient is φ = 297748224.

The previous prime is 1220405917. The next prime is 1220405951. The reversal of 1220405940 is 495040221.

1220405940 is a `hidden beast` number, since 12 + 20 + 40 + 594 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3516847 + ... + 3517193.

Almost surely, 2^1220405940 is an apocalyptic number.

1220405940 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 1220405940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2079798336).

1220405940 is an abundant number, since it is smaller than the sum of its proper divisors (2939190732).

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

1220405940 is a wasteful number, since it uses less digits than its factorization.

1220405940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548 (or 537 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1220405940 is about 34934.3089240363. The cubic root of 1220405940 is about 1068.6482303834.

The spelling of 1220405940 in words is "one billion, two hundred twenty million, four hundred five thousand, nine hundred forty".