181990919140801 has 9 divisors (see below), whose sum is σ = 193326237310441. Its totient is φ = 171285355109632.

The previous prime is 181990919140787. The next prime is 181990919140847. The reversal of 181990919140801 is 108041919099181.

The square root of 181990919140801 is 13490401.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 30056698795201 + 151934220345600 = 5482399^2 + 12326160^2 .

It is not a de Polignac number, because 181990919140801 - 2⁵ = 181990919140769 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 181990919140801.

It is not an unprimeable number, because it can be changed into a prime (181990919740801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 228940041 + ... + 229733593.

Almost surely, 2^{181990919140801} is an apocalyptic number.

181990919140801 is the 13490401-st square number.

181990919140801 is the 6745201-st centered octagonal number.

It is an amenable number.

181990919140801 is a deficient number, since it is larger than the sum of its proper divisors (11335318169640).

181990919140801 is an frugal number, since it uses more digits than its factorization.

181990919140801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587140 (or 793570 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 61.

The spelling of 181990919140801 in words is "one hundred eighty-one trillion, nine hundred ninety billion, nine hundred nineteen million, one hundred forty thousand, eight hundred one".