31790729 has 2 divisors, whose sum is σ = 31790730. Its totient is φ = 31790728.

The previous prime is 31790723. The next prime is 31790809. The reversal of 31790729 is 92709713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21855625 + 9935104 = 4675^2 + 3152^2 .

It is an emirp because it is prime and its reverse (92709713) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31790729 - 2¹² = 31786633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31790692 and 31790701.

It is not a weakly prime, because it can be changed into another prime (31790723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15895364 + 15895365.

It is an arithmetic number, because the mean of its divisors is an integer number (15895365).

Almost surely, 2^31790729 is an apocalyptic number.

It is an amenable number.

31790729 is a deficient number, since it is larger than the sum of its proper divisors (1).

31790729 is an equidigital number, since it uses as much as digits as its factorization.

31790729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 31790729 is about 5638.3267908130. The cubic root of 31790729 is about 316.7866191303.

The spelling of 31790729 in words is "thirty-one million, seven hundred ninety thousand, seven hundred twenty-nine".