1981152001 has 4 divisors (see below), whose sum is σ = 2097690372. Its totient is φ = 1864613632.

The previous prime is 1981151993. The next prime is 1981152049. The reversal of 1981152001 is 1002511891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1002511891 = 5867 ⋅170873.

It can be written as a sum of positive squares in 2 ways, for example, as 1517180401 + 463971600 = 38951^2 + 21540^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981152001 - 2³ = 1981151993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981152101) 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, 58269160 + ... + 58269193.

It is an arithmetic number, because the mean of its divisors is an integer number (524422593).

Almost surely, 2^1981152001 is an apocalyptic number.

It is an amenable number.

1981152001 is a deficient number, since it is larger than the sum of its proper divisors (116538371).

1981152001 is a wasteful number, since it uses less digits than its factorization.

1981152001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116538370.

The product of its (nonzero) digits is 720, while the sum is 28.

The square root of 1981152001 is about 44510.1336888579. The cubic root of 1981152001 is about 1255.9507197404.

Adding to 1981152001 its reverse (1002511891), we get a palindrome (2983663892).

The spelling of 1981152001 in words is "one billion, nine hundred eighty-one million, one hundred fifty-two thousand, one".