31005420646 has 4 divisors (see below), whose sum is σ = 46508130972. Its totient is φ = 15502710322.

The previous prime is 31005420637. The next prime is 31005420697. The reversal of 31005420646 is 64602450013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64602450013 = 2551 ⋅25324363.

It is a super-2 number, since 2×31005420646² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7751355160 + ... + 7751355163.

It is an arithmetic number, because the mean of its divisors is an integer number (11627032743).

Almost surely, 2^31005420646 is an apocalyptic number.

31005420646 is a deficient number, since it is larger than the sum of its proper divisors (15502710326).

31005420646 is a wasteful number, since it uses less digits than its factorization.

31005420646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15502710325.

The product of its (nonzero) digits is 17280, while the sum is 31.

Adding to 31005420646 its reverse (64602450013), we get a palindrome (95607870659).

The spelling of 31005420646 in words is "thirty-one billion, five million, four hundred twenty thousand, six hundred forty-six".