20431643626540 has 12 divisors (see below), whose sum is σ = 42906451615776. Its totient is φ = 8172657450608.

The previous prime is 20431643626531. The next prime is 20431643626601. The reversal of 20431643626540 is 4562634613402.

It is a happy number.

It is a super-2 number, since 2×20431643626540² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510791090644 + ... + 510791090683.

It is an arithmetic number, because the mean of its divisors is an integer number (3575537634648).

Almost surely, 2^{20431643626540} is an apocalyptic number.

20431643626540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20431643626540 is an abundant number, since it is smaller than the sum of its proper divisors (22474807989236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20431643626540 is a wasteful number, since it uses less digits than its factorization.

20431643626540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021582181336 (or 1021582181334 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 46.

The spelling of 20431643626540 in words is "twenty trillion, four hundred thirty-one billion, six hundred forty-three million, six hundred twenty-six thousand, five hundred forty".