1221953804840 has 64 divisors (see below), whose sum is σ = 2776816753920. Its totient is φ = 483924064000.

The previous prime is 1221953804839. The next prime is 1221953804849. The reversal of 1221953804840 is 484083591221.

It is a super-2 number, since 2×1221953804840² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221953804849) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1987910 + ... + 2528970.

It is an arithmetic number, because the mean of its divisors is an integer number (43387761780).

Almost surely, 2^{1221953804840} is an apocalyptic number.

1221953804840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221953804840 is an abundant number, since it is smaller than the sum of its proper divisors (1554862949080).

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

1221953804840 is a wasteful number, since it uses less digits than its factorization.

1221953804840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541634 (or 541630 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 47.

The spelling of 1221953804840 in words is "one trillion, two hundred twenty-one billion, nine hundred fifty-three million, eight hundred four thousand, eight hundred forty".