6621745 has 8 divisors (see below), whose sum is σ = 8557416. Its totient is φ = 4889856.

The previous prime is 6621731. The next prime is 6621749. The reversal of 6621745 is 5471266.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6561 + 6615184 = 81^2 + 2572^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 6621745 - 2⁹ = 6621233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6621749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50872 + ... + 51001.

It is an arithmetic number, because the mean of its divisors is an integer number (1069677).

Almost surely, 2^6621745 is an apocalyptic number.

6621745 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6621745 is a deficient number, since it is larger than the sum of its proper divisors (1935671).

6621745 is a wasteful number, since it uses less digits than its factorization.

6621745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101891.

The product of its digits is 10080, while the sum is 31.

The square root of 6621745 is about 2573.2751504649. The cubic root of 6621745 is about 187.7835236530.

The spelling of 6621745 in words is "six million, six hundred twenty-one thousand, seven hundred forty-five".