20021677551 has 8 divisors (see below), whose sum is σ = 29661744560. Its totient is φ = 13347785016.

The previous prime is 20021677549. The next prime is 20021677561. The reversal of 20021677551 is 15577612002.

20021677551 is a `hidden beast` number, since 20 + 0 + 2 + 16 + 77 + 551 = 666.

It is not a de Polignac number, because 20021677551 - 2¹ = 20021677549 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 (20021677561) 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 7 ways as a sum of consecutive naturals, for example, 370771780 + ... + 370771833.

It is an arithmetic number, because the mean of its divisors is an integer number (3707718070).

Almost surely, 2^20021677551 is an apocalyptic number.

20021677551 is a deficient number, since it is larger than the sum of its proper divisors (9640067009).

20021677551 is an equidigital number, since it uses as much as digits as its factorization.

20021677551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 741543622 (or 741543616 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The spelling of 20021677551 in words is "twenty billion, twenty-one million, six hundred seventy-seven thousand, five hundred fifty-one".