16391031 has 4 divisors (see below), whose sum is σ = 21854712. Its totient is φ = 10927352.

The previous prime is 16391029. The next prime is 16391057. The reversal of 16391031 is 13019361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13019361 = 3 ⋅4339787.

It is a cyclic number.

It is not a de Polignac number, because 16391031 - 2¹ = 16391029 is a prime.

It is a super-2 number, since 2×16391031² = 537331794485922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16390992 and 16391010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16391071) 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, 2731836 + ... + 2731841.

It is an arithmetic number, because the mean of its divisors is an integer number (5463678).

Almost surely, 2^16391031 is an apocalyptic number.

16391031 is a deficient number, since it is larger than the sum of its proper divisors (5463681).

16391031 is an equidigital number, since it uses as much as digits as its factorization.

16391031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5463680.

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 16391031 is about 4048.5838264756. The cubic root of 16391031 is about 254.0204945540.

The spelling of 16391031 in words is "sixteen million, three hundred ninety-one thousand, thirty-one".