26401658646 has 96 divisors (see below), whose sum is σ = 61853912064. Its totient is φ = 7489609600.

The previous prime is 26401658629. The next prime is 26401658671. The reversal of 26401658646 is 64685610462.

It is a junction number, because it is equal to n+sod(n) for n = 26401658595 and 26401658604.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 767986 + ... + 801626.

It is an arithmetic number, because the mean of its divisors is an integer number (644311584).

Almost surely, 2^26401658646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 26401658646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30926956032).

26401658646 is an abundant number, since it is smaller than the sum of its proper divisors (35452253418).

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

26401658646 is a wasteful number, since it uses less digits than its factorization.

26401658646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33738 (or 33727 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 48.

The spelling of 26401658646 in words is "twenty-six billion, four hundred one million, six hundred fifty-eight thousand, six hundred forty-six".