690440645 has 8 divisors (see below), whose sum is σ = 839016960. Its totient is φ = 545360400.

The previous prime is 690440633. The next prime is 690440693. The reversal of 690440645 is 546044096.

It is a happy number.

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

It is not a de Polignac number, because 690440645 - 2²⁰ = 689392069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 690440599 and 690440608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 873581 + ... + 874370.

It is an arithmetic number, because the mean of its divisors is an integer number (104877120).

Almost surely, 2^690440645 is an apocalyptic number.

It is an amenable number.

690440645 is a deficient number, since it is larger than the sum of its proper divisors (148576315).

690440645 is a wasteful number, since it uses less digits than its factorization.

690440645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748035.

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 690440645 is about 26276.2372686806. The cubic root of 690440645 is about 883.8436577283.

The spelling of 690440645 in words is "six hundred ninety million, four hundred forty thousand, six hundred forty-five".