812667491890 has 8 divisors (see below), whose sum is σ = 1462801485420. Its totient is φ = 325066996752.

The previous prime is 812667491863. The next prime is 812667491893. The reversal of 812667491890 is 98194766218.

It can be written as a sum of positive squares in 2 ways, for example, as 812631934521 + 35557369 = 901461^2 + 5963^2 .

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

It is not an unprimeable number, because it can be changed into a prime (812667491893) 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, 40633374585 + ... + 40633374604.

Almost surely, 2^812667491890 is an apocalyptic number.

812667491890 is a deficient number, since it is larger than the sum of its proper divisors (650133993530).

812667491890 is a wasteful number, since it uses less digits than its factorization.

812667491890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81266749196.

The product of its (nonzero) digits is 10450944, while the sum is 61.

The spelling of 812667491890 in words is "eight hundred twelve billion, six hundred sixty-seven million, four hundred ninety-one thousand, eight hundred ninety".