149781 has 4 divisors (see below), whose sum is σ = 199712. Its totient is φ = 99852.

The previous prime is 149771. The next prime is 149791. The reversal of 149781 is 187941.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (149771) and next prime (149791).

It is not a de Polignac number, because 149781 - 2⁵ = 149749 is a prime.

It is a super-2 number, since 2×149781² = 44868695922, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (149711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24961 + ... + 24966.

It is an arithmetic number, because the mean of its divisors is an integer number (49928).

2¹⁴⁹⁷⁸¹ is an apocalyptic number.

It is an amenable number.

149781 is a deficient number, since it is larger than the sum of its proper divisors (49931).

149781 is an equidigital number, since it uses as much as digits as its factorization.

149781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49930.

The product of its digits is 2016, while the sum is 30.

The square root of 149781 is about 387.0155035654. The cubic root of 149781 is about 53.1070578395.

The spelling of 149781 in words is "one hundred forty-nine thousand, seven hundred eighty-one".