1801992901 has 4 divisors (see below), whose sum is σ = 1815748704. Its totient is φ = 1788237100.

The previous prime is 1801992883. The next prime is 1801992917. The reversal of 1801992901 is 1092991081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1801992901 - 2²¹ = 1799895749 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801992601) 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, 6877705 + ... + 6877966.

It is an arithmetic number, because the mean of its divisors is an integer number (453937176).

Almost surely, 2^1801992901 is an apocalyptic number.

It is an amenable number.

1801992901 is a deficient number, since it is larger than the sum of its proper divisors (13755803).

1801992901 is a wasteful number, since it uses less digits than its factorization.

1801992901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13755802.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 1801992901 is about 42449.8869374230. The cubic root of 1801992901 is about 1216.8891678473.

The spelling of 1801992901 in words is "one billion, eight hundred one million, nine hundred ninety-two thousand, nine hundred one".