1221397413 has 16 divisors (see below), whose sum is σ = 1701866496. Its totient is φ = 778402800.

The previous prime is 1221397391. The next prime is 1221397423. The reversal of 1221397413 is 3147931221.

It is not a de Polignac number, because 1221397413 - 2¹⁶ = 1221331877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221397423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94663 + ... + 106788.

It is an arithmetic number, because the mean of its divisors is an integer number (106366656).

Almost surely, 2^1221397413 is an apocalyptic number.

It is an amenable number.

1221397413 is a deficient number, since it is larger than the sum of its proper divisors (480469083).

1221397413 is a wasteful number, since it uses less digits than its factorization.

1221397413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201544.

The product of its digits is 9072, while the sum is 33.

The square root of 1221397413 is about 34948.4965771061. The cubic root of 1221397413 is about 1068.9375464311.

The spelling of 1221397413 in words is "one billion, two hundred twenty-one million, three hundred ninety-seven thousand, four hundred thirteen".