1221152090 has 16 divisors (see below), whose sum is σ = 2222772840. Its totient is φ = 482972160.

The previous prime is 1221152083. The next prime is 1221152099. The reversal of 1221152090 is 902511221.

It can be written as a sum of positive squares in 4 ways, for example, as 831918649 + 389233441 = 28843^2 + 19729^2 .

It is a super-2 number, since 2×1221152090² = 2982424853822736200, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221152099) 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, 685151 + ... + 686930.

Almost surely, 2^1221152090 is an apocalyptic number.

1221152090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221152090 is a deficient number, since it is larger than the sum of its proper divisors (1001620750).

1221152090 is a wasteful number, since it uses less digits than its factorization.

1221152090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372177.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 1221152090 is about 34944.9866218318. The cubic root of 1221152090 is about 1068.8659747156.

The spelling of 1221152090 in words is "one billion, two hundred twenty-one million, one hundred fifty-two thousand, ninety".