1221320404197 has 24 divisors (see below), whose sum is σ = 1841356153728. Its totient is φ = 778590727200.

The previous prime is 1221320404193. The next prime is 1221320404207. The reversal of 1221320404197 is 7914040231221.

1221320404197 is a `hidden beast` number, since 1 + 2 + 213 + 20 + 4 + 0 + 419 + 7 = 666.

It is not a de Polignac number, because 1221320404197 - 2² = 1221320404193 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221320404193) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 113454 + ... + 1567007.

It is an arithmetic number, because the mean of its divisors is an integer number (76723173072).

Almost surely, 2^{1221320404197} is an apocalyptic number.

It is an amenable number.

1221320404197 is a deficient number, since it is larger than the sum of its proper divisors (620035749531).

1221320404197 is a wasteful number, since it uses less digits than its factorization.

1221320404197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1684001 (or 1683998 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 1221320404197 in words is "one trillion, two hundred twenty-one billion, three hundred twenty million, four hundred four thousand, one hundred ninety-seven".