1221221013 has 8 divisors (see below), whose sum is σ = 1637707488. Its totient is φ = 809440944.

The previous prime is 1221221003. The next prime is 1221221033. The reversal of 1221221013 is 3101221221.

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

It is not a de Polignac number, because 1221221013 - 2⁵ = 1221220981 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221220983 and 1221221001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221003) 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, 1175995 + ... + 1177032.

It is an arithmetic number, because the mean of its divisors is an integer number (204713436).

Almost surely, 2^1221221013 is an apocalyptic number.

It is an amenable number.

1221221013 is a deficient number, since it is larger than the sum of its proper divisors (416486475).

1221221013 is a wasteful number, since it uses less digits than its factorization.

1221221013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353203.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221221013 is about 34945.9727722666. The cubic root of 1221221013 is about 1068.8860836122.

Adding to 1221221013 its reverse (3101221221), we get a palindrome (4322442234).

The spelling of 1221221013 in words is "one billion, two hundred twenty-one million, two hundred twenty-one thousand, thirteen".