491071951 has 4 divisors (see below), whose sum is σ = 493216600. Its totient is φ = 488927304.

The previous prime is 491071943. The next prime is 491071969. The reversal of 491071951 is 159170194.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 159170194 = 2 ⋅79585097.

It is a cyclic number.

It is not a de Polignac number, because 491071951 - 2³ = 491071943 is a prime.

It is a super-2 number, since 2×491071951² = 482303322117892802, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 491071951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491071901) 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, 1071981 + ... + 1072438.

It is an arithmetic number, because the mean of its divisors is an integer number (123304150).

Almost surely, 2^491071951 is an apocalyptic number.

491071951 is a deficient number, since it is larger than the sum of its proper divisors (2144649).

491071951 is a wasteful number, since it uses less digits than its factorization.

491071951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144648.

The product of its (nonzero) digits is 11340, while the sum is 37.

The square root of 491071951 is about 22160.1432982731. The cubic root of 491071951 is about 788.9479940427.

The spelling of 491071951 in words is "four hundred ninety-one million, seventy-one thousand, nine hundred fifty-one".