621316778 has 4 divisors (see below), whose sum is σ = 931975170. Its totient is φ = 310658388.

The previous prime is 621316763. The next prime is 621316807. The reversal of 621316778 is 877613126.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 525922489 + 95394289 = 22933^2 + 9767^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155329193 + ... + 155329196.

Almost surely, 2^621316778 is an apocalyptic number.

621316778 is a deficient number, since it is larger than the sum of its proper divisors (310658392).

621316778 is a wasteful number, since it uses less digits than its factorization.

621316778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310658391.

The product of its digits is 84672, while the sum is 41.

The square root of 621316778 is about 24926.2267100338. The cubic root of 621316778 is about 853.3051376521.

The spelling of 621316778 in words is "six hundred twenty-one million, three hundred sixteen thousand, seven hundred seventy-eight".