31450381 has 4 divisors (see below), whose sum is σ = 31478812. Its totient is φ = 31421952.

The previous prime is 31450369. The next prime is 31450387. The reversal of 31450381 is 18305413.

31450381 = 3965² + 3966².

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

It can be written as a sum of positive squares in 2 ways, for example, as 15721225 + 15729156 = 3965^2 + 3966^2 .

It is a cyclic number.

It is not a de Polignac number, because 31450381 - 2¹³ = 31442189 is a prime.

It is a super-2 number, since 2×31450381² = 1978252930090322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31450387) 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, 12486 + ... + 14791.

It is an arithmetic number, because the mean of its divisors is an integer number (7869703).

Almost surely, 2^31450381 is an apocalyptic number.

31450381 is the 3966-th centered square number.

It is an amenable number.

31450381 is a deficient number, since it is larger than the sum of its proper divisors (28431).

31450381 is a wasteful number, since it uses less digits than its factorization.

31450381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28430.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 31450381 is about 5608.0639261692. The cubic root of 31450381 is about 315.6520665740.

Adding to 31450381 its reverse (18305413), we get a palindrome (49755794).

The spelling of 31450381 in words is "thirty-one million, four hundred fifty thousand, three hundred eighty-one".