1213711815 has 16 divisors (see below), whose sum is σ = 1973775456. Its totient is φ = 636700800.

The previous prime is 1213711813. The next prime is 1213711823. The reversal of 1213711815 is 5181173121.

It is not a de Polignac number, because 1213711815 - 2¹ = 1213711813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213711813) 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, 662316 + ... + 664145.

It is an arithmetic number, because the mean of its divisors is an integer number (123360966).

Almost surely, 2^1213711815 is an apocalyptic number.

1213711815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1213711815 is a deficient number, since it is larger than the sum of its proper divisors (760063641).

1213711815 is a wasteful number, since it uses less digits than its factorization.

1213711815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326530.

The product of its digits is 1680, while the sum is 30.

The square root of 1213711815 is about 34838.3669967466. The cubic root of 1213711815 is about 1066.6907438684.

Adding to 1213711815 its reverse (5181173121), we get a palindrome (6394884936).

The spelling of 1213711815 in words is "one billion, two hundred thirteen million, seven hundred eleven thousand, eight hundred fifteen".