6620491 has 4 divisors (see below), whose sum is σ = 6628392.
Its totient is φ = 6612592.
The previous prime is 6620489. The next prime is 6620501. The reversal of 6620491 is 1940266.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1940266 = 2 ⋅970133.
It is a cyclic number.
It is not a de Polignac number, because 6620491 - 21 = 6620489 is a prime.
It is a Duffinian number.
6620491 is a lucky number.
It is not an unprimeable number, because it can be changed into a prime (6620401) 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, 2521 + ... + 4426.
It is an arithmetic number, because the mean of its divisors is an integer number (1657098).
Almost surely, 26620491 is an apocalyptic number.
6620491 is a deficient number, since it is larger than the sum of its proper divisors (7901).
6620491 is an equidigital number, since it uses as much as digits as its factorization.
6620491 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 7900.
The product of its (nonzero) digits is 2592, while the sum is 28.
The square root of 6620491 is about 2573.0314805692.
The cubic root of 6620491 is about 187.7716690031.
The spelling of 6620491 in words is "six million, six hundred twenty thousand, four hundred ninety-one".