1215623081 has 4 divisors (see below), whose sum is σ = 1215696000. Its totient is φ = 1215550164.

The previous prime is 1215623051. The next prime is 1215623099. The reversal of 1215623081 is 1803265121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215623081 is a prime.

It is a super-2 number, since 2×1215623081² = 2955478950119865122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1215623011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2240 + ... + 49358.

It is an arithmetic number, because the mean of its divisors is an integer number (303924000).

Almost surely, 2^1215623081 is an apocalyptic number.

It is an amenable number.

1215623081 is a deficient number, since it is larger than the sum of its proper divisors (72919).

1215623081 is an equidigital number, since it uses as much as digits as its factorization.

1215623081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72918.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 1215623081 is about 34865.7866826492. The cubic root of 1215623081 is about 1067.2503661535.

The spelling of 1215623081 in words is "one billion, two hundred fifteen million, six hundred twenty-three thousand, eighty-one".