31650397 has 4 divisors (see below), whose sum is σ = 32741820. Its totient is φ = 30558976.

The previous prime is 31650343. The next prime is 31650407. The reversal of 31650397 is 79305613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79305613 = 359 ⋅220907.

It can be written as a sum of positive squares in 2 ways, for example, as 15280281 + 16370116 = 3909^2 + 4046^2 .

It is a cyclic number.

It is not a de Polignac number, because 31650397 - 2¹⁵ = 31617629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31650337) 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, 545668 + ... + 545725.

It is an arithmetic number, because the mean of its divisors is an integer number (8185455).

Almost surely, 2^31650397 is an apocalyptic number.

It is an amenable number.

31650397 is a deficient number, since it is larger than the sum of its proper divisors (1091423).

31650397 is a wasteful number, since it uses less digits than its factorization.

31650397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1091422.

The product of its (nonzero) digits is 17010, while the sum is 34.

The square root of 31650397 is about 5625.8685551655. The cubic root of 31650397 is about 316.3198072191.

The spelling of 31650397 in words is "thirty-one million, six hundred fifty thousand, three hundred ninety-seven".