1221490271 has 4 divisors (see below), whose sum is σ = 1228804752. Its totient is φ = 1214175792.

The previous prime is 1221490223. The next prime is 1221490313. The reversal of 1221490271 is 1720941221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1720941221 = 17791 ⋅96731.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221490271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221490211) 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, 3656990 + ... + 3657323.

It is an arithmetic number, because the mean of its divisors is an integer number (307201188).

Almost surely, 2^1221490271 is an apocalyptic number.

1221490271 is a deficient number, since it is larger than the sum of its proper divisors (7314481).

1221490271 is an equidigital number, since it uses as much as digits as its factorization.

1221490271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7314480.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 1221490271 is about 34949.8250496337. The cubic root of 1221490271 is about 1068.9646347717.

The spelling of 1221490271 in words is "one billion, two hundred twenty-one million, four hundred ninety thousand, two hundred seventy-one".