20770343557 has 4 divisors (see below), whose sum is σ = 20770637740. Its totient is φ = 20770049376.

The previous prime is 20770343551. The next prime is 20770343567. The reversal of 20770343557 is 75534307702.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 149670756 + 20620672801 = 12234^2 + 143599^2 .

It is a 3-Lehmer number, since φ(20770343557) divides (20770343557-1)³.

It is a cyclic number.

It is not a de Polignac number, because 20770343557 - 2¹⁵ = 20770310789 is a prime.

It is a super-4 number, since 4×20770343557⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20770343551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29419 + ... + 205927.

It is an arithmetic number, because the mean of its divisors is an integer number (5192659435).

It is a Poulet number, since it divides 2^20770343556-1.

Almost surely, 2^20770343557 is an apocalyptic number.

20770343557 is the 117673-rd pentagonal number.

It is an amenable number.

20770343557 is a deficient number, since it is larger than the sum of its proper divisors (294183).

20770343557 is a wasteful number, since it uses less digits than its factorization.

20770343557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294182.

The product of its (nonzero) digits is 617400, while the sum is 43.

The spelling of 20770343557 in words is "twenty billion, seven hundred seventy million, three hundred forty-three thousand, five hundred fifty-seven".