9139745821 has 8 divisors (see below), whose sum is σ = 9463786200. Its totient is φ = 8816297280.

The previous prime is 9139745767. The next prime is 9139745843. The reversal of 9139745821 is 1285479319.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1752343321 + 7387402500 = 41861^2 + 85950^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9139745821 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 (9139745861) 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, 116410 + ... + 178411.

It is an arithmetic number, because the mean of its divisors is an integer number (1182973275).

Almost surely, 2^9139745821 is an apocalyptic number.

It is an amenable number.

9139745821 is a deficient number, since it is larger than the sum of its proper divisors (324040379).

9139745821 is a wasteful number, since it uses less digits than its factorization.

9139745821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295919.

The product of its digits is 544320, while the sum is 49.

The square root of 9139745821 is about 95602.0178709634. The cubic root of 9139745821 is about 2090.7946140998.

The spelling of 9139745821 in words is "nine billion, one hundred thirty-nine million, seven hundred forty-five thousand, eight hundred twenty-one".