1261022215 has 4 divisors (see below), whose sum is σ = 1513226664. Its totient is φ = 1008817768.

The previous prime is 1261022207. The next prime is 1261022227. The reversal of 1261022215 is 5122201621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261022215 - 2³ = 1261022207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126102217 + ... + 126102226.

It is an arithmetic number, because the mean of its divisors is an integer number (378306666).

Almost surely, 2^1261022215 is an apocalyptic number.

1261022215 is a deficient number, since it is larger than the sum of its proper divisors (252204449).

1261022215 is an equidigital number, since it uses as much as digits as its factorization.

1261022215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252204448.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1261022215 is about 35510.8746020145. The cubic root of 1261022215 is about 1080.3743029877.

Adding to 1261022215 its reverse (5122201621), we get a palindrome (6383223836).

The spelling of 1261022215 in words is "one billion, two hundred sixty-one million, twenty-two thousand, two hundred fifteen".