1221571 has 4 divisors (see below), whose sum is σ = 1315552. Its totient is φ = 1127592.

The previous prime is 1221559. The next prime is 1221589. The reversal of 1221571 is 1751221.

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 1221571 - 2⁷ = 1221443 is a prime.

It is a Duffinian number.

1221571 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1221541) 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, 46971 + ... + 46996.

It is an arithmetic number, because the mean of its divisors is an integer number (328888).

2^1221571 is an apocalyptic number.

1221571 is a deficient number, since it is larger than the sum of its proper divisors (93981).

1221571 is an equidigital number, since it uses as much as digits as its factorization.

1221571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93980.

The product of its digits is 140, while the sum is 19.

The square root of 1221571 is about 1105.2470312107. The cubic root of 1221571 is about 106.8988183750.

Adding to 1221571 its reverse (1751221), we get a palindrome (2972792).

It can be divided in two parts, 12 and 21571, that multiplied together give a palindrome (258852).

The spelling of 1221571 in words is "one million, two hundred twenty-one thousand, five hundred seventy-one".