20415510645640 has 256 divisors, whose sum is σ = 54369181117440. Its totient is φ = 6814629888000.

The previous prime is 20415510645631. The next prime is 20415510645641. The reversal of 20415510645640 is 4654601551402.

It is not an unprimeable number, because it can be changed into a prime (20415510645641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1260753384 + ... + 1260769576.

It is an arithmetic number, because the mean of its divisors is an integer number (212379613740).

Almost surely, 2^{20415510645640} is an apocalyptic number.

20415510645640 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 20415510645640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27184590558720).

20415510645640 is an abundant number, since it is smaller than the sum of its proper divisors (33953670471800).

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

20415510645640 is a wasteful number, since it uses less digits than its factorization.

20415510645640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20384 (or 20380 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 43.

The spelling of 20415510645640 in words is "twenty trillion, four hundred fifteen billion, five hundred ten million, six hundred forty-five thousand, six hundred forty".