1221637041955 has 8 divisors (see below), whose sum is σ = 1599233945904. Its totient is φ = 888463303200.

The previous prime is 1221637041953. The next prime is 1221637041971. The reversal of 1221637041955 is 5591407361221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221637041955 - 2¹ = 1221637041953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221637041953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11105791236 + ... + 11105791345.

It is an arithmetic number, because the mean of its divisors is an integer number (199904243238).

Almost surely, 2^{1221637041955} is an apocalyptic number.

1221637041955 is a deficient number, since it is larger than the sum of its proper divisors (377596903949).

1221637041955 is a wasteful number, since it uses less digits than its factorization.

1221637041955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22211582597.

The product of its (nonzero) digits is 453600, while the sum is 46.

The spelling of 1221637041955 in words is "one trillion, two hundred twenty-one billion, six hundred thirty-seven million, forty-one thousand, nine hundred fifty-five".