981438777523 has 4 divisors (see below), whose sum is σ = 981837901080. Its totient is φ = 981039653968.

The previous prime is 981438777511. The next prime is 981438777547. The reversal of 981438777523 is 325777834189.

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

It is a cyclic number.

It is not a de Polignac number, because 981438777523 - 2¹³ = 981438769331 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981438777023) 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, 199558090 + ... + 199563007.

It is an arithmetic number, because the mean of its divisors is an integer number (245459475270).

Almost surely, 2^981438777523 is an apocalyptic number.

981438777523 is a deficient number, since it is larger than the sum of its proper divisors (399123557).

981438777523 is a wasteful number, since it uses less digits than its factorization.

981438777523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399123556.

The product of its digits is 71124480, while the sum is 64.

The spelling of 981438777523 in words is "nine hundred eighty-one billion, four hundred thirty-eight million, seven hundred seventy-seven thousand, five hundred twenty-three".