491029781 has 8 divisors (see below), whose sum is σ = 540973728. Its totient is φ = 441970000.

The previous prime is 491029753. The next prime is 491029807. The reversal of 491029781 is 187920194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491029781 is a prime.

It is a super-2 number, since 2×491029781² = 482220491657815922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491029081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 219875 + ... + 222096.

It is an arithmetic number, because the mean of its divisors is an integer number (67621716).

Almost surely, 2^491029781 is an apocalyptic number.

It is an amenable number.

491029781 is a deficient number, since it is larger than the sum of its proper divisors (49943947).

491029781 is a wasteful number, since it uses less digits than its factorization.

491029781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442083.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 491029781 is about 22159.1917948286. The cubic root of 491029781 is about 788.9254101903.

The spelling of 491029781 in words is "four hundred ninety-one million, twenty-nine thousand, seven hundred eighty-one".