647690 has 16 divisors (see below), whose sum is σ = 1175040. Its totient is φ = 257040.

The previous prime is 647687. The next prime is 647693. The reversal of 647690 is 96746.

It is an interprime number because it is at equal distance from previous prime (647687) and next prime (647693).

It is a super-2 number, since 2×647690² = 839004672200, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647690.

It is not an unprimeable number, because it can be changed into a prime (647693) 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, 2255 + ... + 2525.

It is an arithmetic number, because the mean of its divisors is an integer number (73440).

2⁶⁴⁷⁶⁹⁰ is an apocalyptic number.

647690 is a deficient number, since it is larger than the sum of its proper divisors (527350).

647690 is a wasteful number, since it uses less digits than its factorization.

647690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 647690 is about 804.7918985676. The cubic root of 647690 is about 86.5211727159.

The spelling of 647690 in words is "six hundred forty-seven thousand, six hundred ninety".