149313781 has 4 divisors (see below), whose sum is σ = 151416864. Its totient is φ = 147210700.

The previous prime is 149313757. The next prime is 149313809. The reversal of 149313781 is 187313941.

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, and also an emirpimes, since its reverse is a distinct semiprime: 187313941 = 47 ⋅3985403.

It is a cyclic number.

It is not a de Polignac number, because 149313781 - 2¹⁹ = 148789493 is a prime.

It is a super-2 number, since 2×149313781² = 44589210393031922, which contains 22 as substring.

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 149313781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (149313881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1051435 + ... + 1051576.

It is an arithmetic number, because the mean of its divisors is an integer number (37854216).

Almost surely, 2^149313781 is an apocalyptic number.

It is an amenable number.

149313781 is a deficient number, since it is larger than the sum of its proper divisors (2103083).

149313781 is an equidigital number, since it uses as much as digits as its factorization.

149313781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2103082.

The product of its digits is 18144, while the sum is 37.

The square root of 149313781 is about 12219.4018266035. The cubic root of 149313781 is about 530.5178053241.

The spelling of 149313781 in words is "one hundred forty-nine million, three hundred thirteen thousand, seven hundred eighty-one".