1215817201 has 4 divisors (see below), whose sum is σ = 1279807600. Its totient is φ = 1151826804.

The previous prime is 1215817171. The next prime is 1215817231. The reversal of 1215817201 is 1027185121.

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.

It is an interprime number because it is at equal distance from previous prime (1215817171) and next prime (1215817231).

It is a cyclic number.

It is not a de Polignac number, because 1215817201 - 2¹⁵ = 1215784433 is a prime.

It is a super-2 number, since 2×1215817201² = 2956422932494948802, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1215817201.

It is not an unprimeable number, because it can be changed into a prime (1215817231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31995171 + ... + 31995208.

It is an arithmetic number, because the mean of its divisors is an integer number (319951900).

Almost surely, 2^1215817201 is an apocalyptic number.

It is an amenable number.

1215817201 is a deficient number, since it is larger than the sum of its proper divisors (63990399).

1215817201 is an equidigital number, since it uses as much as digits as its factorization.

1215817201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63990398.

The product of its (nonzero) digits is 1120, while the sum is 28.

The square root of 1215817201 is about 34868.5703893922. The cubic root of 1215817201 is about 1067.3071720329.

The spelling of 1215817201 in words is "one billion, two hundred fifteen million, eight hundred seventeen thousand, two hundred one".