621797778 has 48 divisors (see below), whose sum is σ = 1606640256. Its totient is φ = 169931520.

The previous prime is 621797777. The next prime is 621797779. The reversal of 621797778 is 877797126.

621797778 is a `hidden beast` number, since 621 + 7 + 9 + 7 + 7 + 7 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (621797777) and next prime (621797779).

It is not an unprimeable number, because it can be changed into a prime (621797773) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104383 + ... + 110178.

It is an arithmetic number, because the mean of its divisors is an integer number (33471672).

Almost surely, 2^621797778 is an apocalyptic number.

621797778 is an abundant number, since it is smaller than the sum of its proper divisors (984842478).

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

621797778 is a wasteful number, since it uses less digits than its factorization.

621797778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214599 (or 214596 counting only the distinct ones).

The product of its digits is 2074464, while the sum is 54.

The square root of 621797778 is about 24935.8733153664. The cubic root of 621797778 is about 853.5252797308.

The spelling of 621797778 in words is "six hundred twenty-one million, seven hundred ninety-seven thousand, seven hundred seventy-eight".