20778129450 has 96 divisors (see below), whose sum is σ = 61659595200. Its totient is φ = 5114612160.

The previous prime is 20778129439. The next prime is 20778129457. The reversal of 20778129450 is 5492187702.

It is a happy number.

20778129450 is a `hidden beast` number, since 2 + 0 + 7 + 78 + 129 + 450 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 20778129396 and 20778129405.

It is not an unprimeable number, because it can be changed into a prime (20778129457) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 574420 + ... + 609519.

It is an arithmetic number, because the mean of its divisors is an integer number (642287450).

Almost surely, 2^20778129450 is an apocalyptic number.

20778129450 is an abundant number, since it is smaller than the sum of its proper divisors (40881465750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20778129450 is a wasteful number, since it uses less digits than its factorization.

20778129450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1183973 (or 1183962 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 20778129450 in words is "twenty billion, seven hundred seventy-eight million, one hundred twenty-nine thousand, four hundred fifty".