1220400440 has 64 divisors (see below), whose sum is σ = 3141365760. Its totient is φ = 417997440.

The previous prime is 1220400439. The next prime is 1220400451. The reversal of 1220400440 is 440040221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 410399 + ... + 413361.

It is an arithmetic number, because the mean of its divisors is an integer number (49083840).

Almost surely, 2^1220400440 is an apocalyptic number.

1220400440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220400440 is an abundant number, since it is smaller than the sum of its proper divisors (1920965320).

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

1220400440 is a wasteful number, since it uses less digits than its factorization.

1220400440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4452 (or 4448 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 1220400440 is about 34934.2302047719. The cubic root of 1220400440 is about 1068.6466250230.

Adding to 1220400440 its reverse (440040221), we get a palindrome (1660440661).

The spelling of 1220400440 in words is "one billion, two hundred twenty million, four hundred thousand, four hundred forty".