181620977 has 2 divisors, whose sum is σ = 181620978. Its totient is φ = 181620976.

The previous prime is 181620961. The next prime is 181621001. The reversal of 181620977 is 779026181.

181620977 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153784801 + 27836176 = 12401^2 + 5276^2 .

It is a cyclic number.

It is not a de Polignac number, because 181620977 - 2⁴ = 181620961 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (181620377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90810488 + 90810489.

It is an arithmetic number, because the mean of its divisors is an integer number (90810489).

Almost surely, 2^181620977 is an apocalyptic number.

It is an amenable number.

181620977 is a deficient number, since it is larger than the sum of its proper divisors (1).

181620977 is an equidigital number, since it uses as much as digits as its factorization.

181620977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 181620977 is about 13476.6827149711. The cubic root of 181620977 is about 566.3114413040.

The spelling of 181620977 in words is "one hundred eighty-one million, six hundred twenty thousand, nine hundred seventy-seven".