90821739 has 4 divisors (see below), whose sum is σ = 121095656. Its totient is φ = 60547824.

The previous prime is 90821737. The next prime is 90821749. The reversal of 90821739 is 93712809.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93712809 = 3 ⋅31237603.

It is not a de Polignac number, because 90821739 - 2¹ = 90821737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90821697 and 90821706.

It is not an unprimeable number, because it can be changed into a prime (90821737) 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, 15136954 + ... + 15136959.

It is an arithmetic number, because the mean of its divisors is an integer number (30273914).

Almost surely, 2^90821739 is an apocalyptic number.

90821739 is a deficient number, since it is larger than the sum of its proper divisors (30273917).

90821739 is a wasteful number, since it uses less digits than its factorization.

90821739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30273916.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 90821739 is about 9530.0440187861. The cubic root of 90821739 is about 449.5002501439.

The spelling of 90821739 in words is "ninety million, eight hundred twenty-one thousand, seven hundred thirty-nine".