149997621 has 4 divisors (see below), whose sum is σ = 199996832. Its totient is φ = 99998412.

The previous prime is 149997619. The next prime is 149997637. The reversal of 149997621 is 126799941.

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: 126799941 = 3 ⋅42266647.

It is not a de Polignac number, because 149997621 - 2¹ = 149997619 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 (149997691) 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, 24999601 + ... + 24999606.

It is an arithmetic number, because the mean of its divisors is an integer number (49999208).

Almost surely, 2^149997621 is an apocalyptic number.

It is an amenable number.

149997621 is a deficient number, since it is larger than the sum of its proper divisors (49999211).

149997621 is an equidigital number, since it uses as much as digits as its factorization.

149997621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49999210.

The product of its digits is 244944, while the sum is 48.

The square root of 149997621 is about 12247.3515912625. The cubic root of 149997621 is about 531.3264756156.

The spelling of 149997621 in words is "one hundred forty-nine million, nine hundred ninety-seven thousand, six hundred twenty-one".