31545421 has 4 divisors (see below), whose sum is σ = 33401052. Its totient is φ = 29689792.

The previous prime is 31545407. The next prime is 31545439. The reversal of 31545421 is 12454513.

It is a happy number.

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 28355625 + 3189796 = 5325^2 + 1786^2 .

It is a cyclic number.

It is not a de Polignac number, because 31545421 - 2¹³ = 31537229 is a prime.

It is a super-2 number, since 2×31545421² = 1990227172134482, 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 (31545401) 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, 927790 + ... + 927823.

It is an arithmetic number, because the mean of its divisors is an integer number (8350263).

Almost surely, 2^31545421 is an apocalyptic number.

It is an amenable number.

31545421 is a deficient number, since it is larger than the sum of its proper divisors (1855631).

31545421 is a wasteful number, since it uses less digits than its factorization.

31545421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1855630.

The product of its digits is 2400, while the sum is 25.

The square root of 31545421 is about 5616.5310468295. The cubic root of 31545421 is about 315.9697034726.

Adding to 31545421 its reverse (12454513), we get a palindrome (43999934).

The spelling of 31545421 in words is "thirty-one million, five hundred forty-five thousand, four hundred twenty-one".