20400346031 has 4 divisors (see below), whose sum is σ = 21969603432. Its totient is φ = 18831088632.

The previous prime is 20400345997. The next prime is 20400346039. The reversal of 20400346031 is 13064300402.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20400346031 is a prime.

It is a super-2 number, since 2×20400346031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20400345988 and 20400346006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400346039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 784628681 + ... + 784628706.

It is an arithmetic number, because the mean of its divisors is an integer number (5492400858).

Almost surely, 2^20400346031 is an apocalyptic number.

20400346031 is a deficient number, since it is larger than the sum of its proper divisors (1569257401).

20400346031 is a wasteful number, since it uses less digits than its factorization.

20400346031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1569257400.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 20400346031 its reverse (13064300402), we get a palindrome (33464646433).

The spelling of 20400346031 in words is "twenty billion, four hundred million, three hundred forty-six thousand, thirty-one".