20642407778 has 8 divisors (see below), whose sum is σ = 31264229568. Its totient is φ = 10220997924.

The previous prime is 20642407771. The next prime is 20642407787. The reversal of 20642407778 is 87770424602.

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

It is a super-2 number, since 2×20642407778² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20642407771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50102726 + ... + 50103137.

It is an arithmetic number, because the mean of its divisors is an integer number (3908028696).

Almost surely, 2^20642407778 is an apocalyptic number.

20642407778 is a deficient number, since it is larger than the sum of its proper divisors (10621821790).

20642407778 is a wasteful number, since it uses less digits than its factorization.

20642407778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100205968.

The product of its (nonzero) digits is 1053696, while the sum is 47.

The spelling of 20642407778 in words is "twenty billion, six hundred forty-two million, four hundred seven thousand, seven hundred seventy-eight".