6438921681031 has 90 divisors (see below), whose sum is σ = 7925181577888. Its totient is φ = 5225618034000.

The previous prime is 6438921681007. The next prime is 6438921681047. The reversal of 6438921681031 is 1301861298346.

It is not a de Polignac number, because 6438921681031 - 2¹³ = 6438921672839 is a prime.

It is a super-2 number, since 2×6438921681031² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6438921681031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6438921681001) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 49152073836 + ... + 49152073966.

Almost surely, 2^{6438921681031} is an apocalyptic number.

6438921681031 is a deficient number, since it is larger than the sum of its proper divisors (1486259896857).

6438921681031 is an frugal number, since it uses more digits than its factorization.

6438921681031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 52.

The spelling of 6438921681031 in words is "six trillion, four hundred thirty-eight billion, nine hundred twenty-one million, six hundred eighty-one thousand, thirty-one".