31278398449 has 3 divisors (see below), whose sum is σ = 31278575307. Its totient is φ = 31278221592.

The previous prime is 31278398423. The next prime is 31278398453. The reversal of 31278398449 is 94489387213.

The square root of 31278398449 is 176857.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 30368290225 + 910108224 = 174265^2 + 30168^2 .

It is not a de Polignac number, because 31278398449 - 2³¹ = 29130914801 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31278398393 and 31278398402.

It is not an unprimeable number, because it can be changed into a prime (31278398419) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 88429 + ... + 265285.

It is an arithmetic number, because the mean of its divisors is an integer number (10426191769).

Almost surely, 2^31278398449 is an apocalyptic number.

31278398449 is the 176857-th square number.

31278398449 is the 88429-th centered octagonal number.

It is an amenable number.

31278398449 is a deficient number, since it is larger than the sum of its proper divisors (176858).

31278398449 is an frugal number, since it uses more digits than its factorization.

31278398449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353714 (or 176857 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 58.

The spelling of 31278398449 in words is "thirty-one billion, two hundred seventy-eight million, three hundred ninety-eight thousand, four hundred forty-nine".