1221871095 has 32 divisors (see below), whose sum is σ = 2286547200. Its totient is φ = 617365152.

The previous prime is 1221871093. The next prime is 1221871097. The reversal of 1221871095 is 5901781221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1221871093) and next prime (1221871097).

It is not a de Polignac number, because 1221871095 - 2¹ = 1221871093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221871093) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 235617 + ... + 240746.

It is an arithmetic number, because the mean of its divisors is an integer number (71454600).

Almost surely, 2^1221871095 is an apocalyptic number.

1221871095 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221871095 is a deficient number, since it is larger than the sum of its proper divisors (1064676105).

1221871095 is a wasteful number, since it uses less digits than its factorization.

1221871095 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476396 (or 476390 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The square root of 1221871095 is about 34955.2727782233. The cubic root of 1221871095 is about 1069.0757135905.

The spelling of 1221871095 in words is "one billion, two hundred twenty-one million, eight hundred seventy-one thousand, ninety-five".