31505020401 has 32 divisors (see below), whose sum is σ = 43399784448. Its totient is φ = 20318096960.

The previous prime is 31505020367. The next prime is 31505020499. The reversal of 31505020401 is 10402050513.

It is a cyclic number.

It is not a de Polignac number, because 31505020401 - 2¹⁴ = 31505004017 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31505020301) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7405591 + ... + 7409843.

It is an arithmetic number, because the mean of its divisors is an integer number (1356243264).

Almost surely, 2^31505020401 is an apocalyptic number.

It is an amenable number.

31505020401 is a deficient number, since it is larger than the sum of its proper divisors (11894764047).

31505020401 is a wasteful number, since it uses less digits than its factorization.

31505020401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4901.

The product of its (nonzero) digits is 600, while the sum is 21.

Adding to 31505020401 its reverse (10402050513), we get a palindrome (41907070914).

The spelling of 31505020401 in words is "thirty-one billion, five hundred five million, twenty thousand, four hundred one".