1928890386981 has 8 divisors (see below), whose sum is σ = 2857615388160. Its totient is φ = 1285926924636.

The previous prime is 1928890386949. The next prime is 1928890387031. The reversal of 1928890386981 is 1896830988291.

1928890386981 is a `hidden beast` number, since 1 + 9 + 2 + 88 + 90 + 386 + 9 + 81 = 666.

It is not a de Polignac number, because 1928890386981 - 2⁵ = 1928890386949 is a prime.

It is a super-2 number, since 2×1928890386981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1928890386911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35720192325 + ... + 35720192378.

It is an arithmetic number, because the mean of its divisors is an integer number (357201923520).

Almost surely, 2^{1928890386981} is an apocalyptic number.

It is an amenable number.

1928890386981 is a deficient number, since it is larger than the sum of its proper divisors (928725001179).

1928890386981 is an equidigital number, since it uses as much as digits as its factorization.

1928890386981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71440384712 (or 71440384706 counting only the distinct ones).

The product of its (nonzero) digits is 107495424, while the sum is 72.

The spelling of 1928890386981 in words is "one trillion, nine hundred twenty-eight billion, eight hundred ninety million, three hundred eighty-six thousand, nine hundred eighty-one".