181409157 has 6 divisors (see below), whose sum is σ = 262035462. Its totient is φ = 120939432.

The previous prime is 181409147. The next prime is 181409167. The reversal of 181409157 is 751904181.

It is an interprime number because it is at equal distance from previous prime (181409147) and next prime (181409167).

It can be written as a sum of positive squares in only one way, i.e., 120428676 + 60980481 = 10974^2 + 7809^2 .

It is not a de Polignac number, because 181409157 - 2⁴ = 181409141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181409147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10078278 + ... + 10078295.

It is an arithmetic number, because the mean of its divisors is an integer number (43672577).

Almost surely, 2^181409157 is an apocalyptic number.

It is an amenable number.

181409157 is a deficient number, since it is larger than the sum of its proper divisors (80626305).

181409157 is a wasteful number, since it uses less digits than its factorization.

181409157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20156579 (or 20156576 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The square root of 181409157 is about 13468.8216633824. The cubic root of 181409157 is about 566.0911973732.

The spelling of 181409157 in words is "one hundred eighty-one million, four hundred nine thousand, one hundred fifty-seven".