491873623 has 2 divisors, whose sum is σ = 491873624. Its totient is φ = 491873622.

The previous prime is 491873567. The next prime is 491873633. The reversal of 491873623 is 326378194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491873623 - 2¹³ = 491865431 is a prime.

It is a super-2 number, since 2×491873623² = 483879322006292258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 491873623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491873633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245936811 + 245936812.

It is an arithmetic number, because the mean of its divisors is an integer number (245936812).

Almost surely, 2^491873623 is an apocalyptic number.

491873623 is a deficient number, since it is larger than the sum of its proper divisors (1).

491873623 is an equidigital number, since it uses as much as digits as its factorization.

491873623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 43.

The square root of 491873623 is about 22178.2240722741. The cubic root of 491873623 is about 789.3770782498.

The spelling of 491873623 in words is "four hundred ninety-one million, eight hundred seventy-three thousand, six hundred twenty-three".