20626042640 has 80 divisors (see below), whose sum is σ = 55123400448. Its totient is φ = 7030875648.

The previous prime is 20626042627. The next prime is 20626042687. The reversal of 20626042640 is 4624062602.

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

It is a junction number, because it is equal to n+sod(n) for n = 20626042597 and 20626042606.

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, 9572 + ... + 203331.

Almost surely, 2^20626042640 is an apocalyptic number.

20626042640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20626042640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27561700224).

20626042640 is an abundant number, since it is smaller than the sum of its proper divisors (34497357808).

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

20626042640 is a wasteful number, since it uses less digits than its factorization.

20626042640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213096 (or 213090 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The spelling of 20626042640 in words is "twenty billion, six hundred twenty-six million, forty-two thousand, six hundred forty".