642667247173451 has 4 divisors (see below), whose sum is σ = 645997129283352. Its totient is φ = 639337365063552.

The previous prime is 642667247173423. The next prime is 642667247173477. The reversal of 642667247173451 is 154371742766246.

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

It is a cyclic number.

It is not a de Polignac number, because 642667247173451 - 2²² = 642667242979147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642667247173151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1664941054661 + ... + 1664941055046.

It is an arithmetic number, because the mean of its divisors is an integer number (161499282320838).

Almost surely, 2^{642667247173451} is an apocalyptic number.

642667247173451 is a deficient number, since it is larger than the sum of its proper divisors (3329882109901).

642667247173451 is a wasteful number, since it uses less digits than its factorization.

642667247173451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3329882109900.

The product of its digits is 284497920, while the sum is 65.

The spelling of 642667247173451 in words is "six hundred forty-two trillion, six hundred sixty-seven billion, two hundred forty-seven million, one hundred seventy-three thousand, four hundred fifty-one".