1981398040802 has 8 divisors (see below), whose sum is σ = 2972397272412. Its totient is φ = 990598950000.

The previous prime is 1981398040799. The next prime is 1981398041023. The reversal of 1981398040802 is 2080408931891.

It can be written as a sum of positive squares in 2 ways, for example, as 1554961614361 + 426436426441 = 1246981^2 + 653021^2 .

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

It is a super-3 number, since 3×1981398040802³ (a number of 38 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50010449 + ... + 50050052.

Almost surely, 2^{1981398040802} is an apocalyptic number.

1981398040802 is a deficient number, since it is larger than the sum of its proper divisors (990999231610).

1981398040802 is a wasteful number, since it uses less digits than its factorization.

1981398040802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100070404.

The product of its (nonzero) digits is 995328, while the sum is 53.

The spelling of 1981398040802 in words is "one trillion, nine hundred eighty-one billion, three hundred ninety-eight million, forty thousand, eight hundred two".