20942778377 has 8 divisors (see below), whose sum is σ = 21057518664. Its totient is φ = 20828251008.

The previous prime is 20942778349. The next prime is 20942778379. The reversal of 20942778377 is 77387724902.

It can be written as a sum of positive squares in 4 ways, for example, as 1794030736 + 19148747641 = 42356^2 + 138379^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20942778377 is a prime.

It is a super-2 number, since 2×20942778377² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20942778379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146063 + ... + 251435.

It is an arithmetic number, because the mean of its divisors is an integer number (2632189833).

Almost surely, 2^20942778377 is an apocalyptic number.

It is an amenable number.

20942778377 is a deficient number, since it is larger than the sum of its proper divisors (114740287).

20942778377 is a wasteful number, since it uses less digits than its factorization.

20942778377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106459.

The product of its (nonzero) digits is 8297856, while the sum is 56.

The spelling of 20942778377 in words is "twenty billion, nine hundred forty-two million, seven hundred seventy-eight thousand, three hundred seventy-seven".