1311221015 has 32 divisors (see below), whose sum is σ = 1733659200. Its totient is φ = 946114560.

The previous prime is 1311220979. The next prime is 1311221039. The reversal of 1311221015 is 5101221131.

It is not a de Polignac number, because 1311221015 - 2⁸ = 1311220759 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311220984 and 1311221002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 693191 + ... + 695079.

It is an arithmetic number, because the mean of its divisors is an integer number (54176850).

Almost surely, 2^1311221015 is an apocalyptic number.

1311221015 is a deficient number, since it is larger than the sum of its proper divisors (422438185).

1311221015 is a wasteful number, since it uses less digits than its factorization.

1311221015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 1311221015 is about 36210.7858931562. The cubic root of 1311221015 is about 1094.5240288000.

Adding to 1311221015 its reverse (5101221131), we get a palindrome (6412442146).

The spelling of 1311221015 in words is "one billion, three hundred eleven million, two hundred twenty-one thousand, fifteen".