1215091 has 8 divisors (see below), whose sum is σ = 1257984. Its totient is φ = 1173000.

The previous prime is 1215083. The next prime is 1215103. The reversal of 1215091 is 1905121.

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 1215091 - 2³ = 1215083 is a prime.

It is a super-2 number, since 2×1215091² = 2952892276562, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

1215091 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1215391) 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, 4716 + ... + 4966.

It is an arithmetic number, because the mean of its divisors is an integer number (157248).

2^1215091 is an apocalyptic number.

1215091 is a deficient number, since it is larger than the sum of its proper divisors (42893).

1215091 is a wasteful number, since it uses less digits than its factorization.

1215091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401.

The product of its (nonzero) digits is 90, while the sum is 19.

The square root of 1215091 is about 1102.3116619178. The cubic root of 1215091 is about 106.7094630788.

The spelling of 1215091 in words is "one million, two hundred fifteen thousand, ninety-one".