1321251515 has 8 divisors (see below), whose sum is σ = 1600320240. Its totient is φ = 1047122272.

The previous prime is 1321251493. The next prime is 1321251517. The reversal of 1321251515 is 5151521231.

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

It is a cyclic number.

It is not a de Polignac number, because 1321251515 - 2¹² = 1321247419 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1321251517) 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, 1234280 + ... + 1235349.

It is an arithmetic number, because the mean of its divisors is an integer number (200040030).

Almost surely, 2^1321251515 is an apocalyptic number.

1321251515 is a deficient number, since it is larger than the sum of its proper divisors (279068725).

1321251515 is a wasteful number, since it uses less digits than its factorization.

1321251515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2469741.

The product of its digits is 1500, while the sum is 26.

The square root of 1321251515 is about 36349.0235769821. The cubic root of 1321251515 is about 1097.3078836896.

Adding to 1321251515 its reverse (5151521231), we get a palindrome (6472772746).

The spelling of 1321251515 in words is "one billion, three hundred twenty-one million, two hundred fifty-one thousand, five hundred fifteen".