31148021 has 4 divisors (see below), whose sum is σ = 31439232. Its totient is φ = 30856812.

The previous prime is 31148009. The next prime is 31148023. The reversal of 31148021 is 12084113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31148021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31147984 and 31148002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31148023) 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 3 ways as a sum of consecutive naturals, for example, 145445 + ... + 145658.

It is an arithmetic number, because the mean of its divisors is an integer number (7859808).

Almost surely, 2^31148021 is an apocalyptic number.

It is an amenable number.

31148021 is a deficient number, since it is larger than the sum of its proper divisors (291211).

31148021 is a wasteful number, since it uses less digits than its factorization.

31148021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291210.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 31148021 is about 5581.0412111003. The cubic root of 31148021 is about 314.6372611241.

The spelling of 31148021 in words is "thirty-one million, one hundred forty-eight thousand, twenty-one".