26138640 has 80 divisors (see below), whose sum is σ = 88405056. Its totient is φ = 6336000.

The previous prime is 26138633. The next prime is 26138653. The reversal of 26138640 is 4683162.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 26138598 and 26138607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2311 + ... + 7590.

Almost surely, 2^26138640 is an apocalyptic number.

26138640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

26138640 is an abundant number, since it is smaller than the sum of its proper divisors (62266416).

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

26138640 is a wasteful number, since it uses less digits than its factorization.

26138640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9928 (or 9922 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 26138640 is about 5112.5962093637. The cubic root of 26138640 is about 296.7752383544.

The spelling of 26138640 in words is "twenty-six million, one hundred thirty-eight thousand, six hundred forty".