1321651 has 2 divisors, whose sum is σ = 1321652. Its totient is φ = 1321650.

The previous prime is 1321637. The next prime is 1321657. The reversal of 1321651 is 1561231.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1321651 - 2⁹ = 1321139 is a prime.

It is a super-2 number, since 2×1321651² = 3493522731602, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1321657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660825 + 660826.

It is an arithmetic number, because the mean of its divisors is an integer number (660826).

2^1321651 is an apocalyptic number.

1321651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321651 is an equidigital number, since it uses as much as digits as its factorization.

1321651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 19.

The square root of 1321651 is about 1149.6308103039. The cubic root of 1321651 is about 109.7418464166.

Adding to 1321651 its reverse (1561231), we get a palindrome (2882882).

The spelling of 1321651 in words is "one million, three hundred twenty-one thousand, six hundred fifty-one".