1664397567 has 12 divisors (see below), whose sum is σ = 2747577040. Its totient is φ = 951084288.

The previous prime is 1664397557. The next prime is 1664397569. The reversal of 1664397567 is 7657934661.

It is a happy number.

1664397567 is a `hidden beast` number, since 16 + 64 + 3 + 9 + 7 + 567 = 666.

It is not a de Polignac number, because 1664397567 - 2¹⁶ = 1664332031 is a prime.

It is a super-2 number, since 2×1664397567² = 5540438522071038978, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664397569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13209442 + ... + 13209567.

Almost surely, 2^1664397567 is an apocalyptic number.

1664397567 is a deficient number, since it is larger than the sum of its proper divisors (1083179473).

1664397567 is a wasteful number, since it uses less digits than its factorization.

1664397567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26419022 (or 26419019 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 54.

The square root of 1664397567 is about 40797.0288991735. The cubic root of 1664397567 is about 1185.0927941007.

The spelling of 1664397567 in words is "one billion, six hundred sixty-four million, three hundred ninety-seven thousand, five hundred sixty-seven".