491521078 has 4 divisors (see below), whose sum is σ = 737281620. Its totient is φ = 245760538.

The previous prime is 491521073. The next prime is 491521117. The reversal of 491521078 is 870125194.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491521073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122880268 + ... + 122880271.

It is an arithmetic number, because the mean of its divisors is an integer number (184320405).

Almost surely, 2^491521078 is an apocalyptic number.

491521078 is a deficient number, since it is larger than the sum of its proper divisors (245760542).

491521078 is a wasteful number, since it uses less digits than its factorization.

491521078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245760541.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 491521078 is about 22170.2746487273. The cubic root of 491521078 is about 789.1884407334.

The spelling of 491521078 in words is "four hundred ninety-one million, five hundred twenty-one thousand, seventy-eight".