20158747781077 has 4 divisors (see below), whose sum is σ = 20158786480896. Its totient is φ = 20158709081260.

The previous prime is 20158747781069. The next prime is 20158747781101. The reversal of 20158747781077 is 77018774785102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20158747781077 - 2³ = 20158747781069 is a prime.

It is a super-2 number, since 2×20158747781077² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20158747781057) 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 3 ways as a sum of consecutive naturals, for example, 18557749 + ... + 19613962.

It is an arithmetic number, because the mean of its divisors is an integer number (5039696620224).

Almost surely, 2^{20158747781077} is an apocalyptic number.

It is an amenable number.

20158747781077 is a deficient number, since it is larger than the sum of its proper divisors (38699819).

20158747781077 is an equidigital number, since it uses as much as digits as its factorization.

20158747781077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38699818.

The product of its (nonzero) digits is 43025920, while the sum is 64.

It can be divided in two parts, 2015874 and 7781077, that added together give a triangular number (9796951 = T₄₄₂₆).

The spelling of 20158747781077 in words is "twenty trillion, one hundred fifty-eight billion, seven hundred forty-seven million, seven hundred eighty-one thousand, seventy-seven".