491917790 has 128 divisors (see below), whose sum is σ = 1197987840. Its totient is φ = 140963328.

The previous prime is 491917787. The next prime is 491917793. The reversal of 491917790 is 97719194.

It is an interprime number because it is at equal distance from previous prime (491917787) and next prime (491917793).

It is a super-2 number, since 2×491917790² = 483966224236968200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491917793) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 397052 + ... + 398288.

It is an arithmetic number, because the mean of its divisors is an integer number (9359280).

Almost surely, 2^491917790 is an apocalyptic number.

491917790 is an abundant number, since it is smaller than the sum of its proper divisors (706070050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491917790 is a wasteful number, since it uses less digits than its factorization.

491917790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306.

The product of its (nonzero) digits is 142884, while the sum is 47.

The square root of 491917790 is about 22179.2197788831. The cubic root of 491917790 is about 789.4007044905.

The spelling of 491917790 in words is "four hundred ninety-one million, nine hundred seventeen thousand, seven hundred ninety".