20690907155 has 4 divisors (see below), whose sum is σ = 24829088592. Its totient is φ = 16552725720.

The previous prime is 20690907131. The next prime is 20690907161. The reversal of 20690907155 is 55170909602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20690907155 - 2¹² = 20690903059 is a prime.

It is a super-2 number, since 2×20690907155² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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, 2069090711 + ... + 2069090720.

It is an arithmetic number, because the mean of its divisors is an integer number (6207272148).

Almost surely, 2^20690907155 is an apocalyptic number.

20690907155 is a deficient number, since it is larger than the sum of its proper divisors (4138181437).

20690907155 is an equidigital number, since it uses as much as digits as its factorization.

20690907155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4138181436.

The product of its (nonzero) digits is 170100, while the sum is 44.

The spelling of 20690907155 in words is "twenty billion, six hundred ninety million, nine hundred seven thousand, one hundred fifty-five".