31603261 has 2 divisors, whose sum is σ = 31603262. Its totient is φ = 31603260.

The previous prime is 31603259. The next prime is 31603309. The reversal of 31603261 is 16230613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23707161 + 7896100 = 4869^2 + 2810^2 .

It is a cyclic number.

It is not a de Polignac number, because 31603261 - 2¹ = 31603259 is a prime.

It is a super-2 number, since 2×31603261² = 1997532211668242, which contains 22 as substring.

Together with 31603259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31603361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15801630 + 15801631.

It is an arithmetic number, because the mean of its divisors is an integer number (15801631).

Almost surely, 2^31603261 is an apocalyptic number.

It is an amenable number.

31603261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31603261 is an equidigital number, since it uses as much as digits as its factorization.

31603261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 31603261 is about 5621.6777744727. The cubic root of 31603261 is about 316.1627006246.

Adding to 31603261 its reverse (16230613), we get a palindrome (47833874).

The spelling of 31603261 in words is "thirty-one million, six hundred three thousand, two hundred sixty-one".