1606640651 has 8 divisors (see below), whose sum is σ = 2003084544. Its totient is φ = 1251927720.

The previous prime is 1606640647. The next prime is 1606640657. The reversal of 1606640651 is 1560466061.

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

It is a cyclic number.

It is not a de Polignac number, because 1606640651 - 2² = 1606640647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1606640657) 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, 10432655 + ... + 10432808.

It is an arithmetic number, because the mean of its divisors is an integer number (250385568).

Almost surely, 2^1606640651 is an apocalyptic number.

1606640651 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1606640651 is a deficient number, since it is larger than the sum of its proper divisors (396443893).

1606640651 is a wasteful number, since it uses less digits than its factorization.

1606640651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20865481.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1606640651 is about 40082.9221863876. The cubic root of 1606640651 is about 1171.2229769304. Note that the first 3 decimals are identical.

The spelling of 1606640651 in words is "one billion, six hundred six million, six hundred forty thousand, six hundred fifty-one".