639847016555 has 4 divisors (see below), whose sum is σ = 767816419872. Its totient is φ = 511877613240.

The previous prime is 639847016531. The next prime is 639847016579. The reversal of 639847016555 is 555610748936.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (639847016531) and next prime (639847016579).

It is not a de Polignac number, because 639847016555 - 2¹² = 639847012459 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639847016494 and 639847016503.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63984701651 + ... + 63984701660.

It is an arithmetic number, because the mean of its divisors is an integer number (191954104968).

Almost surely, 2^639847016555 is an apocalyptic number.

639847016555 is a deficient number, since it is larger than the sum of its proper divisors (127969403317).

639847016555 is a wasteful number, since it uses less digits than its factorization.

639847016555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127969403316.

The product of its (nonzero) digits is 27216000, while the sum is 59.

The spelling of 639847016555 in words is "six hundred thirty-nine billion, eight hundred forty-seven million, sixteen thousand, five hundred fifty-five".