1664220505 has 8 divisors (see below), whose sum is σ = 1997754624. Its totient is φ = 1330916400.

The previous prime is 1664220433. The next prime is 1664220527. The reversal of 1664220505 is 5050224661.

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

It is not a de Polignac number, because 1664220505 - 2¹³ = 1664212313 is a prime.

It is a Duffinian 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, 41161 + ... + 70870.

It is an arithmetic number, because the mean of its divisors is an integer number (249719328).

Almost surely, 2^1664220505 is an apocalyptic number.

It is an amenable number.

1664220505 is a deficient number, since it is larger than the sum of its proper divisors (333534119).

1664220505 is a wasteful number, since it uses less digits than its factorization.

1664220505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115007.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 1664220505 is about 40794.8588059819. The cubic root of 1664220505 is about 1185.0507684161.

The spelling of 1664220505 in words is "one billion, six hundred sixty-four million, two hundred twenty thousand, five hundred five".