1801920197 has 16 divisors (see below), whose sum is σ = 2250052992. Its totient is φ = 1401904320.

The previous prime is 1801920187. The next prime is 1801920199. The reversal of 1801920197 is 7910291081.

It is a cyclic number.

It is not a de Polignac number, because 1801920197 - 2⁴ = 1801920181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1801920197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801920199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32363 + ... + 68199.

It is an arithmetic number, because the mean of its divisors is an integer number (140628312).

Almost surely, 2^1801920197 is an apocalyptic number.

It is an amenable number.

1801920197 is a deficient number, since it is larger than the sum of its proper divisors (448132795).

1801920197 is a wasteful number, since it uses less digits than its factorization.

1801920197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36508.

The product of its (nonzero) digits is 9072, while the sum is 38.

The square root of 1801920197 is about 42449.0305778589. The cubic root of 1801920197 is about 1216.8728019116.

The spelling of 1801920197 in words is "one billion, eight hundred one million, nine hundred twenty thousand, one hundred ninety-seven".