1521320431 has 2 divisors, whose sum is σ = 1521320432. Its totient is φ = 1521320430.

The previous prime is 1521320417. The next prime is 1521320467. The reversal of 1521320431 is 1340231251.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1521320431 - 2¹⁹ = 1520796143 is a prime.

It is a super-2 number, since 2×1521320431² = 4628831707556051522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1521326431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760660215 + 760660216.

It is an arithmetic number, because the mean of its divisors is an integer number (760660216).

Almost surely, 2^1521320431 is an apocalyptic number.

1521320431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521320431 is an equidigital number, since it uses as much as digits as its factorization.

1521320431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 1521320431 is about 39004.1078734023. The cubic root of 1521320431 is about 1150.1122589846.

Adding to 1521320431 its reverse (1340231251), we get a palindrome (2861551682).

The spelling of 1521320431 in words is "one billion, five hundred twenty-one million, three hundred twenty thousand, four hundred thirty-one".