31451481 has 6 divisors (see below), whose sum is σ = 45429930. Its totient is φ = 20967648.

The previous prime is 31451461. The next prime is 31451489. The reversal of 31451481 is 18415413.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 31304025 + 147456 = 5595^2 + 384^2 .

It is not a de Polignac number, because 31451481 - 2¹³ = 31443289 is a prime.

It is a super-3 number, since 3×31451481³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31451489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1747296 + ... + 1747313.

It is an arithmetic number, because the mean of its divisors is an integer number (7571655).

Almost surely, 2^31451481 is an apocalyptic number.

It is an amenable number.

31451481 is a deficient number, since it is larger than the sum of its proper divisors (13978449).

31451481 is a wasteful number, since it uses less digits than its factorization.

31451481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3494615 (or 3494612 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 31451481 is about 5608.1619983734. The cubic root of 31451481 is about 315.6557465848.

Adding to 31451481 its reverse (18415413), we get a palindrome (49866894).

The spelling of 31451481 in words is "thirty-one million, four hundred fifty-one thousand, four hundred eighty-one".