1521397 has 2 divisors, whose sum is σ = 1521398. Its totient is φ = 1521396.

The previous prime is 1521391. The next prime is 1521479. The reversal of 1521397 is 7931251.

1521397 is nontrivially palindromic in base 8.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1168561 + 352836 = 1081^2 + 594^2 .

It is a cyclic number.

It is not a de Polignac number, because 1521397 - 2⁷ = 1521269 is a prime.

1521397 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1521391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760698 + 760699.

It is an arithmetic number, because the mean of its divisors is an integer number (760699).

2^1521397 is an apocalyptic number.

It is an amenable number.

1521397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521397 is an equidigital number, since it uses as much as digits as its factorization.

1521397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 28.

The square root of 1521397 is about 1233.4492287889. The cubic root of 1521397 is about 115.0131553948.

It can be divided in two parts, 15 and 21397, that added together give a palindrome (21412).

The spelling of 1521397 in words is "one million, five hundred twenty-one thousand, three hundred ninety-seven".