31505540643 has 12 divisors (see below), whose sum is σ = 45544987488. Its totient is φ = 20986624080.

The previous prime is 31505540629. The next prime is 31505540681. The reversal of 31505540643 is 34604550513.

31505540643 is a `hidden beast` number, since 3 + 1 + 5 + 0 + 5 + 5 + 4 + 0 + 643 = 666.

It is not a de Polignac number, because 31505540643 - 2⁵ = 31505540611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31505540598 and 31505540607.

It is not an unprimeable number, because it can be changed into a prime (31505542643) 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 11 ways as a sum of consecutive naturals, for example, 1410780 + ... + 1432937.

It is an arithmetic number, because the mean of its divisors is an integer number (3795415624).

Almost surely, 2^31505540643 is an apocalyptic number.

31505540643 is a deficient number, since it is larger than the sum of its proper divisors (14039446845).

31505540643 is a wasteful number, since it uses less digits than its factorization.

31505540643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2844954 (or 2844951 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The spelling of 31505540643 in words is "thirty-one billion, five hundred five million, five hundred forty thousand, six hundred forty-three".