1639602971 has 4 divisors (see below), whose sum is σ = 1641071952. Its totient is φ = 1638133992.

The previous prime is 1639602959. The next prime is 1639602977. The reversal of 1639602971 is 1792069361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1792069361 = 101 ⋅17743261.

It is a cyclic number.

It is not a de Polignac number, because 1639602971 - 2³⁰ = 565861147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1639602977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 732815 + ... + 735048.

It is an arithmetic number, because the mean of its divisors is an integer number (410267988).

Almost surely, 2^1639602971 is an apocalyptic number.

1639602971 is a deficient number, since it is larger than the sum of its proper divisors (1468981).

1639602971 is a wasteful number, since it uses less digits than its factorization.

1639602971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1468980.

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 1639602971 is about 40492.0111997416. The cubic root of 1639602971 is about 1179.1785365207.

The spelling of 1639602971 in words is "one billion, six hundred thirty-nine million, six hundred two thousand, nine hundred seventy-one".