20101356661518 has 192 divisors, whose sum is σ = 49496498648064. Its totient is φ = 5892188702400.

The previous prime is 20101356661489. The next prime is 20101356661591. The reversal of 20101356661518 is 81516665310102.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 90042471 + ... + 90265437.

It is an arithmetic number, because the mean of its divisors is an integer number (257794263792).

Almost surely, 2^{20101356661518} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20101356661518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24748249324032).

20101356661518 is an abundant number, since it is smaller than the sum of its proper divisors (29395141986546).

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

20101356661518 is a wasteful number, since it uses less digits than its factorization.

20101356661518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223132 (or 223107 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 20101356661518 in words is "twenty trillion, one hundred one billion, three hundred fifty-six million, six hundred sixty-one thousand, five hundred eighteen".