190181198621 has 4 divisors (see below), whose sum is σ = 190593739644. Its totient is φ = 189768657600.

The previous prime is 190181198539. The next prime is 190181198629. The reversal of 190181198621 is 126891181091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126891181091 = 17 ⋅7464187123.

It can be written as a sum of positive squares in 2 ways, for example, as 136836367396 + 53344831225 = 369914^2 + 230965^2 .

It is a cyclic number.

It is not a de Polignac number, because 190181198621 - 2¹⁴ = 190181182237 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 (190181198629) 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, 206269820 + ... + 206270741.

It is an arithmetic number, because the mean of its divisors is an integer number (47648434911).

Almost surely, 2^190181198621 is an apocalyptic number.

It is an amenable number.

190181198621 is a deficient number, since it is larger than the sum of its proper divisors (412541023).

190181198621 is an equidigital number, since it uses as much as digits as its factorization.

190181198621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412541022.

The product of its (nonzero) digits is 62208, while the sum is 47.

The spelling of 190181198621 in words is "one hundred ninety billion, one hundred eighty-one million, one hundred ninety-eight thousand, six hundred twenty-one".