781398490 has 8 divisors (see below), whose sum is σ = 1406517300. Its totient is φ = 312559392.

The previous prime is 781398473. The next prime is 781398491. The reversal of 781398490 is 94893187.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 765020281 + 16378209 = 27659^2 + 4047^2 .

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

It is a super-2 number, since 2×781398490² = 1221167200348560200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781398491) 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, 39069915 + ... + 39069934.

Almost surely, 2^781398490 is an apocalyptic number.

781398490 is a deficient number, since it is larger than the sum of its proper divisors (625118810).

781398490 is a wasteful number, since it uses less digits than its factorization.

781398490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78139856.

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 781398490 is about 27953.5058624138. The cubic root of 781398490 is about 921.0662220929.

The spelling of 781398490 in words is "seven hundred eighty-one million, three hundred ninety-eight thousand, four hundred ninety".