149709821 has 4 divisors (see below), whose sum is σ = 150127200. Its totient is φ = 149292444.

The previous prime is 149709817. The next prime is 149709823. The reversal of 149709821 is 128907941.

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 a cyclic number.

It is not a de Polignac number, because 149709821 - 2² = 149709817 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 (149709823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208151 + ... + 208868.

It is an arithmetic number, because the mean of its divisors is an integer number (37531800).

Almost surely, 2^149709821 is an apocalyptic number.

It is an amenable number.

149709821 is a deficient number, since it is larger than the sum of its proper divisors (417379).

149709821 is an equidigital number, since it uses as much as digits as its factorization.

149709821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417378.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 149709821 is about 12235.5964709531. The cubic root of 149709821 is about 530.9864398588.

The spelling of 149709821 in words is "one hundred forty-nine million, seven hundred nine thousand, eight hundred twenty-one".