621648906 has 8 divisors (see below), whose sum is σ = 1243297824. Its totient is φ = 207216300.

The previous prime is 621648889. The next prime is 621648913. The reversal of 621648906 is 609846126.

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

621648906 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51804070 + ... + 51804081.

It is an arithmetic number, because the mean of its divisors is an integer number (155412228).

Almost surely, 2^621648906 is an apocalyptic number.

621648906 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.

621648906 is a wasteful number, since it uses less digits than its factorization.

621648906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103608156.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 621648906 is about 24932.8880396957. Note that the first 3 decimals coincide. The cubic root of 621648906 is about 853.4571567482.

The spelling of 621648906 in words is "six hundred twenty-one million, six hundred forty-eight thousand, nine hundred six".