6657690 has 64 divisors (see below), whose sum is σ = 17652096. Its totient is φ = 1596672.

The previous prime is 6657671. The next prime is 6657697. The reversal of 6657690 is 967566.

It is a happy number.

It is a super-2 number, since 2×6657690² = 88649672272200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6657697) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16572 + ... + 16968.

It is an arithmetic number, because the mean of its divisors is an integer number (275814).

Almost surely, 2^6657690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6657690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8826048).

6657690 is an abundant number, since it is smaller than the sum of its proper divisors (10994406).

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

6657690 is a wasteful number, since it uses less digits than its factorization.

6657690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463.

The product of its (nonzero) digits is 68040, while the sum is 39.

The square root of 6657690 is about 2580.2499878888. The cubic root of 6657690 is about 188.1226941657.

It can be divided in two parts, 66576 and 90, that added together give a palindrome (66666).

The spelling of 6657690 in words is "six million, six hundred fifty-seven thousand, six hundred ninety".