1988130781 has 16 divisors (see below), whose sum is σ = 2525867008. Its totient is φ = 1522281600.

The previous prime is 1988130737. The next prime is 1988130791. The reversal of 1988130781 is 1870318891.

It is not a de Polignac number, because 1988130781 - 2¹⁷ = 1987999709 is a prime.

It is a super-2 number, since 2×1988130781² = 7905328004719339922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988130791) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349560 + ... + 355201.

It is an arithmetic number, because the mean of its divisors is an integer number (157866688).

Almost surely, 2^1988130781 is an apocalyptic number.

It is an amenable number.

1988130781 is a deficient number, since it is larger than the sum of its proper divisors (537736227).

1988130781 is a wasteful number, since it uses less digits than its factorization.

1988130781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704812.

The product of its (nonzero) digits is 96768, while the sum is 46.

The square root of 1988130781 is about 44588.4601774944. The cubic root of 1988130781 is about 1257.4237233303.

The spelling of 1988130781 in words is "one billion, nine hundred eighty-eight million, one hundred thirty thousand, seven hundred eighty-one".