20513555040 has 192 divisors, whose sum is σ = 70829966592. Its totient is φ = 4949145600.

The previous prime is 20513554979. The next prime is 20513555057. The reversal of 20513555040 is 4055531502.

It is a happy number.

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 = 20513554989 and 20513555007.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1104874 + ... + 1123286.

It is an arithmetic number, because the mean of its divisors is an integer number (368906076).

Almost surely, 2^20513555040 is an apocalyptic number.

20513555040 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 20513555040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35414983296).

20513555040 is an abundant number, since it is smaller than the sum of its proper divisors (50316411552).

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

20513555040 is a wasteful number, since it uses less digits than its factorization.

20513555040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18653 (or 18645 counting only the distinct ones).

The product of its (nonzero) digits is 15000, while the sum is 30.

The spelling of 20513555040 in words is "twenty billion, five hundred thirteen million, five hundred fifty-five thousand, forty".