20921687762040 has 1024 divisors, whose sum is σ = 80307279360000. Its totient is φ = 4802304319488.

The previous prime is 20921687761991. The next prime is 20921687762099. The reversal of 20921687762040 is 4026778612902.

20921687762040 is a `hidden beast` number, since 2 + 0 + 9 + 2 + 1 + 6 + 8 + 7 + 7 + 620 + 4 + 0 = 666.

It is a super-3 number, since 3×20921687762040³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 4565061589 + ... + 4565066171.

It is an arithmetic number, because the mean of its divisors is an integer number (78425077500).

Almost surely, 2^{20921687762040} is an apocalyptic number.

20921687762040 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 20921687762040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40153639680000).

20921687762040 is an abundant number, since it is smaller than the sum of its proper divisors (59385591597960).

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

20921687762040 is a wasteful number, since it uses less digits than its factorization.

20921687762040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4901 (or 4891 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 54.

The spelling of 20921687762040 in words is "twenty trillion, nine hundred twenty-one billion, six hundred eighty-seven million, seven hundred sixty-two thousand, forty".