20400331 has 8 divisors (see below), whose sum is σ = 23529440. Its totient is φ = 17324928.

The previous prime is 20400307. The next prime is 20400337. The reversal of 20400331 is 13300402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20400331 - 2¹³ = 20392139 is a prime.

It is a super-2 number, since 2×20400331² = 832347009819122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20400337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12606 + ... + 14131.

It is an arithmetic number, because the mean of its divisors is an integer number (2941180).

Almost surely, 2^20400331 is an apocalyptic number.

20400331 is a deficient number, since it is larger than the sum of its proper divisors (3129109).

20400331 is a wasteful number, since it uses less digits than its factorization.

20400331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26853.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 20400331 is about 4516.6725584217. The cubic root of 20400331 is about 273.2409194161.

Adding to 20400331 its reverse (13300402), we get a palindrome (33700733).

The spelling of 20400331 in words is "twenty million, four hundred thousand, three hundred thirty-one".