38149721 has 4 divisors (see below), whose sum is σ = 39080244. Its totient is φ = 37219200.

The previous prime is 38149687. The next prime is 38149753. The reversal of 38149721 is 12794183.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4044121 + 34105600 = 2011^2 + 5840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38149721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (38149781) 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, 465200 + ... + 465281.

It is an arithmetic number, because the mean of its divisors is an integer number (9770061).

Almost surely, 2^38149721 is an apocalyptic number.

It is an amenable number.

38149721 is a deficient number, since it is larger than the sum of its proper divisors (930523).

38149721 is an equidigital number, since it uses as much as digits as its factorization.

38149721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 930522.

The product of its digits is 12096, while the sum is 35.

The square root of 38149721 is about 6176.5460412758. The cubic root of 38149721 is about 336.6385044356.

The spelling of 38149721 in words is "thirty-eight million, one hundred forty-nine thousand, seven hundred twenty-one".