1981802101 has 8 divisors (see below), whose sum is σ = 1993800960. Its totient is φ = 1969834608.

The previous prime is 1981802083. The next prime is 1981802111. The reversal of 1981802101 is 1012081891.

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

It is a cyclic number.

It is not a de Polignac number, because 1981802101 - 2⁹ = 1981801589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981802111) 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, 125680 + ... + 140566.

It is an arithmetic number, because the mean of its divisors is an integer number (249225120).

Almost surely, 2^1981802101 is an apocalyptic number.

It is an amenable number.

1981802101 is a deficient number, since it is larger than the sum of its proper divisors (11998859).

1981802101 is a wasteful number, since it uses less digits than its factorization.

1981802101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15683.

The product of its (nonzero) digits is 1152, while the sum is 31.

The square root of 1981802101 is about 44517.4359212208. The cubic root of 1981802101 is about 1256.0880816171.

Adding to 1981802101 its reverse (1012081891), we get a palindrome (2993883992).

The spelling of 1981802101 in words is "one billion, nine hundred eighty-one million, eight hundred two thousand, one hundred one".