938148821 has 4 divisors (see below), whose sum is σ = 940014432. Its totient is φ = 936283212.

The previous prime is 938148787. The next prime is 938148847. The reversal of 938148821 is 128841839.

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: 128841839 = 7 ⋅18405977.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-938148821 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 (938148121) 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, 932051 + ... + 933056.

It is an arithmetic number, because the mean of its divisors is an integer number (235003608).

Almost surely, 2^938148821 is an apocalyptic number.

It is an amenable number.

938148821 is a deficient number, since it is larger than the sum of its proper divisors (1865611).

938148821 is a wasteful number, since it uses less digits than its factorization.

938148821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1865610.

The product of its digits is 110592, while the sum is 44.

The square root of 938148821 is about 30629.2151548158. The cubic root of 938148821 is about 978.9426403006.

The spelling of 938148821 in words is "nine hundred thirty-eight million, one hundred forty-eight thousand, eight hundred twenty-one".