1650161721 has 8 divisors (see below), whose sum is σ = 2369463040. Its totient is φ = 1015484112.

The previous prime is 1650161719. The next prime is 1650161743. The reversal of 1650161721 is 1271610561.

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

It is not a de Polignac number, because 1650161721 - 2¹ = 1650161719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1650161771) 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, 21155881 + ... + 21155958.

It is an arithmetic number, because the mean of its divisors is an integer number (296182880).

Almost surely, 2^1650161721 is an apocalyptic number.

It is an amenable number.

1650161721 is a deficient number, since it is larger than the sum of its proper divisors (719301319).

1650161721 is a wasteful number, since it uses less digits than its factorization.

1650161721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42311855.

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 1650161721 is about 40622.1826223063. The cubic root of 1650161721 is about 1181.7043553006.

The spelling of 1650161721 in words is "one billion, six hundred fifty million, one hundred sixty-one thousand, seven hundred twenty-one".