20778457755 has 32 divisors (see below), whose sum is σ = 36862426368. Its totient is φ = 9909244800.

The previous prime is 20778457753. The next prime is 20778457759. The reversal of 20778457755 is 55775487702.

It is not a de Polignac number, because 20778457755 - 2¹ = 20778457753 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20778457695 and 20778457704.

It is not an unprimeable number, because it can be changed into a prime (20778457751) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1022149 + ... + 1042278.

It is an arithmetic number, because the mean of its divisors is an integer number (1151950824).

Almost surely, 2^20778457755 is an apocalyptic number.

20778457755 is a deficient number, since it is larger than the sum of its proper divisors (16083968613).

20778457755 is a wasteful number, since it uses less digits than its factorization.

20778457755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2064507.

The product of its (nonzero) digits is 19208000, while the sum is 57.

The spelling of 20778457755 in words is "twenty billion, seven hundred seventy-eight million, four hundred fifty-seven thousand, seven hundred fifty-five".