149181821 has 8 divisors (see below), whose sum is σ = 153497400. Its totient is φ = 144898560.

The previous prime is 149181811. The next prime is 149181847. The reversal of 149181821 is 128181941.

It can be written as a sum of positive squares in 4 ways, for example, as 7214596 + 141967225 = 2686^2 + 11915^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 149181821 - 2²² = 144987517 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 (149181811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1445 + ... + 17333.

It is an arithmetic number, because the mean of its divisors is an integer number (19187175).

Almost surely, 2^149181821 is an apocalyptic number.

It is an amenable number.

149181821 is a deficient number, since it is larger than the sum of its proper divisors (4315579).

149181821 is a wasteful number, since it uses less digits than its factorization.

149181821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16159.

The product of its digits is 4608, while the sum is 35.

The square root of 149181821 is about 12214.0010234157. The cubic root of 149181821 is about 530.3614728838.

The spelling of 149181821 in words is "one hundred forty-nine million, one hundred eighty-one thousand, eight hundred twenty-one".