1215065551 has 8 divisors (see below), whose sum is σ = 1449022464. Its totient is φ = 996202680.

The previous prime is 1215065549. The next prime is 1215065557. The reversal of 1215065551 is 1555605121.

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

It is not a de Polignac number, because 1215065551 - 2¹ = 1215065549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215065557) 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 7 ways as a sum of consecutive naturals, for example, 3773335 + ... + 3773656.

It is an arithmetic number, because the mean of its divisors is an integer number (181127808).

Almost surely, 2^1215065551 is an apocalyptic number.

1215065551 is a deficient number, since it is larger than the sum of its proper divisors (233956913).

1215065551 is an equidigital number, since it uses as much as digits as its factorization.

1215065551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7547021.

The product of its (nonzero) digits is 7500, while the sum is 31.

The square root of 1215065551 is about 34857.7903918192. The cubic root of 1215065551 is about 1067.0871809536.

The spelling of 1215065551 in words is "one billion, two hundred fifteen million, sixty-five thousand, five hundred fifty-one".