391553 has 2 divisors, whose sum is σ = 391554. Its totient is φ = 391552.

The previous prime is 391537. The next prime is 391579. The reversal of 391553 is 355193.

It is an a-pointer prime, because the next prime (391579) can be obtained adding 391553 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368449 + 23104 = 607^2 + 152^2 .

It is an emirp because it is prime and its reverse (355193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 391553 - 2⁴ = 391537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (391453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195776 + 195777.

It is an arithmetic number, because the mean of its divisors is an integer number (195777).

2³⁹¹⁵⁵³ is an apocalyptic number.

It is an amenable number.

391553 is a deficient number, since it is larger than the sum of its proper divisors (1).

391553 is an equidigital number, since it uses as much as digits as its factorization.

391553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2025, while the sum is 26.

The square root of 391553 is about 625.7419595968. The cubic root of 391553 is about 73.1582854286.

The spelling of 391553 in words is "three hundred ninety-one thousand, five hundred fifty-three".