1609651 has 4 divisors (see below), whose sum is σ = 1612192. Its totient is φ = 1607112.

The previous prime is 1609631. The next prime is 1609667. The reversal of 1609651 is 1569061.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1609651 - 2⁷ = 1609523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1609631) 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, 550 + ... + 1876.

It is an arithmetic number, because the mean of its divisors is an integer number (403048).

2^1609651 is an apocalyptic number.

1609651 is a deficient number, since it is larger than the sum of its proper divisors (2541).

1609651 is a wasteful number, since it uses less digits than its factorization.

1609651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2540.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 1609651 is about 1268.7202213254. The cubic root of 1609651 is about 117.1954024064.

The spelling of 1609651 in words is "one million, six hundred nine thousand, six hundred fifty-one".