16491431 has 4 divisors (see below), whose sum is σ = 17990664. Its totient is φ = 14992200.

The previous prime is 16491379. The next prime is 16491443. The reversal of 16491431 is 13419461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13419461 = 11 ⋅1219951.

It is a cyclic number.

It is not a de Polignac number, because 16491431 - 2⁶ = 16491367 is a prime.

It is a super-2 number, since 2×16491431² = 543934592855522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16491394 and 16491403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16491731) 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, 749600 + ... + 749621.

It is an arithmetic number, because the mean of its divisors is an integer number (4497666).

Almost surely, 2^16491431 is an apocalyptic number.

16491431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

16491431 is a deficient number, since it is larger than the sum of its proper divisors (1499233).

16491431 is a wasteful number, since it uses less digits than its factorization.

16491431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1499232.

The product of its digits is 2592, while the sum is 29.

The square root of 16491431 is about 4060.9642943518. The cubic root of 16491431 is about 254.5380898495.

The spelling of 16491431 in words is "sixteen million, four hundred ninety-one thousand, four hundred thirty-one".