1221204431164 has 12 divisors (see below), whose sum is σ = 2151260787088. Its totient is φ = 606558492000.

The previous prime is 1221204431131. The next prime is 1221204431197. The reversal of 1221204431164 is 4611344021221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1221204431131) and next prime (1221204431197).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1010930217 + ... + 1010931424.

Almost surely, 2^{1221204431164} is an apocalyptic number.

It is an amenable number.

1221204431164 is a deficient number, since it is larger than the sum of its proper divisors (930056355924).

1221204431164 is a wasteful number, since it uses less digits than its factorization.

1221204431164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2021861796 (or 2021861794 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

Adding to 1221204431164 its reverse (4611344021221), we get a palindrome (5832548452385).

The spelling of 1221204431164 in words is "one trillion, two hundred twenty-one billion, two hundred four million, four hundred thirty-one thousand, one hundred sixty-four".