1221311207 has 8 divisors (see below), whose sum is σ = 1259711856. Its totient is φ = 1183194432.

The previous prime is 1221311159. The next prime is 1221311209. The reversal of 1221311207 is 7021131221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221311207 - 2¹⁰ = 1221310183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221311209) 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, 62213 + ... + 79454.

It is an arithmetic number, because the mean of its divisors is an integer number (157463982).

Almost surely, 2^1221311207 is an apocalyptic number.

1221311207 is a deficient number, since it is larger than the sum of its proper divisors (38400649).

1221311207 is a wasteful number, since it uses less digits than its factorization.

1221311207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141937.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 1221311207 is about 34947.2632261812. The cubic root of 1221311207 is about 1068.9123973690.

Adding to 1221311207 its reverse (7021131221), we get a palindrome (8242442428).

The spelling of 1221311207 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, two hundred seven".