901801891901 has 4 divisors (see below), whose sum is σ = 903182906172. Its totient is φ = 900420877632.

The previous prime is 901801891889. The next prime is 901801891909. The reversal of 901801891901 is 109198108109.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 109198108109 = 421 ⋅259377929.

It can be written as a sum of positive squares in 2 ways, for example, as 602953803001 + 298848088900 = 776501^2 + 546670^2 .

It is a cyclic number.

It is not a de Polignac number, because 901801891901 - 2¹⁰ = 901801890877 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 (901801891909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 690506156 + ... + 690507461.

It is an arithmetic number, because the mean of its divisors is an integer number (225795726543).

Almost surely, 2^901801891901 is an apocalyptic number.

It is an amenable number.

901801891901 is a deficient number, since it is larger than the sum of its proper divisors (1381014271).

901801891901 is a wasteful number, since it uses less digits than its factorization.

901801891901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381014270.

The product of its (nonzero) digits is 46656, while the sum is 47.

The spelling of 901801891901 in words is "nine hundred one billion, eight hundred one million, eight hundred ninety-one thousand, nine hundred one".