1988735381 has 4 divisors (see below), whose sum is σ = 2037241164. Its totient is φ = 1940229600.

The previous prime is 1988735363. The next prime is 1988735401. The reversal of 1988735381 is 1835378891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1835378891 = 19 ⋅96598889.

It can be written as a sum of positive squares in 2 ways, for example, as 286760356 + 1701975025 = 16934^2 + 41255^2 .

It is a cyclic number.

It is not a de Polignac number, because 1988735381 - 2⁶ = 1988735317 is a prime.

It is a super-2 number, since 2×1988735381² = 7910136831282430322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988735341) 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, 24252830 + ... + 24252911.

It is an arithmetic number, because the mean of its divisors is an integer number (509310291).

Almost surely, 2^1988735381 is an apocalyptic number.

It is an amenable number.

1988735381 is a deficient number, since it is larger than the sum of its proper divisors (48505783).

1988735381 is an equidigital number, since it uses as much as digits as its factorization.

1988735381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48505782.

The product of its digits is 1451520, while the sum is 53.

The square root of 1988735381 is about 44595.2394432410. The cubic root of 1988735381 is about 1257.5511732512.

The spelling of 1988735381 in words is "one billion, nine hundred eighty-eight million, seven hundred thirty-five thousand, three hundred eighty-one".