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BaseRepresentation
bin1001011101000000001101…
…11001100111000010000101
32201121021211120010200200102
410232200012321213002011
510211041311403244041
6112113433002453445
74243603003062002
oct456400671470205
981537746120612
1020787757478021
116695047184876
1223b8981b04285
13b7a37aaa3b61
1451c1c06b48a9
15260b0d49e09b
hex12e806e67085

20787757478021 has 16 divisors (see below), whose sum is σ = 22072447729728. Its totient is φ = 19509991737600.

The previous prime is 20787757478011. The next prime is 20787757478023. The reversal of 20787757478021 is 12087475778702.

It is not a de Polignac number, because 20787757478021 - 26 = 20787757477957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20787757478023) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 12876551 + ... + 14400731.

It is an arithmetic number, because the mean of its divisors is an integer number (1379527983108).

Almost surely, 220787757478021 is an apocalyptic number.

It is an amenable number.

20787757478021 is a deficient number, since it is larger than the sum of its proper divisors (1284690251707).

20787757478021 is a wasteful number, since it uses less digits than its factorization.

20787757478021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1526452.

The product of its (nonzero) digits is 86051840, while the sum is 65.

The spelling of 20787757478021 in words is "twenty trillion, seven hundred eighty-seven billion, seven hundred fifty-seven million, four hundred seventy-eight thousand, twenty-one".