391961 has 2 divisors, whose sum is σ = 391962. Its totient is φ = 391960.

The previous prime is 391939. The next prime is 391967. The reversal of 391961 is 169193.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 265225 + 126736 = 515^2 + 356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-391961 is a prime.

It is a super-3 number, since 3×391961³ = 180654933301910043, which contains 333 as substring.

It is a plaindrome in base 6.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391961.

It is not a weakly prime, because it can be changed into another prime (391967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195980 + 195981.

It is an arithmetic number, because the mean of its divisors is an integer number (195981).

2³⁹¹⁹⁶¹ is an apocalyptic number.

It is an amenable number.

391961 is a deficient number, since it is larger than the sum of its proper divisors (1).

391961 is an equidigital number, since it uses as much as digits as its factorization.

391961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1458, while the sum is 29.

The square root of 391961 is about 626.0678876927. The cubic root of 391961 is about 73.1836870294.

The spelling of 391961 in words is "three hundred ninety-one thousand, nine hundred sixty-one".