149687821 has 8 divisors (see below), whose sum is σ = 155521080. Its totient is φ = 143899392.

The previous prime is 149687807. The next prime is 149687899. The reversal of 149687821 is 128786941.

It can be written as a sum of positive squares in 4 ways, for example, as 114921 + 149572900 = 339^2 + 12230^2 .

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

It is not a de Polignac number, because 149687821 - 2⁹ = 149687309 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 (149687801) 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, 4320 + ... + 17833.

It is an arithmetic number, because the mean of its divisors is an integer number (19440135).

Almost surely, 2^149687821 is an apocalyptic number.

It is an amenable number.

149687821 is a deficient number, since it is larger than the sum of its proper divisors (5833259).

149687821 is a wasteful number, since it uses less digits than its factorization.

149687821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22415.

The product of its digits is 193536, while the sum is 46.

The square root of 149687821 is about 12234.6974216774. The cubic root of 149687821 is about 530.9604289312.

The spelling of 149687821 in words is "one hundred forty-nine million, six hundred eighty-seven thousand, eight hundred twenty-one".