621218778 has 8 divisors (see below), whose sum is σ = 1242437568. Its totient is φ = 207072924.

The previous prime is 621218771. The next prime is 621218797. The reversal of 621218778 is 877812126.

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

621218778 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (621218771) 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, 51768226 + ... + 51768237.

It is an arithmetic number, because the mean of its divisors is an integer number (155304696).

Almost surely, 2^621218778 is an apocalyptic number.

621218778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

621218778 is a wasteful number, since it uses less digits than its factorization.

621218778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103536468.

The product of its digits is 75264, while the sum is 42.

The square root of 621218778 is about 24924.2608315673. The cubic root of 621218778 is about 853.2602714885.

The spelling of 621218778 in words is "six hundred twenty-one million, two hundred eighteen thousand, seven hundred seventy-eight".