642120245 has 8 divisors (see below), whose sum is σ = 829817016. Its totient is φ = 474181056.

The previous prime is 642120223. The next prime is 642120263. The reversal of 642120245 is 542021246.

It can be written as a sum of positive squares in 4 ways, for example, as 154902916 + 487217329 = 12446^2 + 22073^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 642120245 - 2¹² = 642116149 is a prime.

It is a Duffinian number.

It is a congruent 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, 4939322 + ... + 4939451.

It is an arithmetic number, because the mean of its divisors is an integer number (103727127).

Almost surely, 2^642120245 is an apocalyptic number.

642120245 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

642120245 is a deficient number, since it is larger than the sum of its proper divisors (187696771).

642120245 is a wasteful number, since it uses less digits than its factorization.

642120245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9878791.

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 642120245 is about 25340.0916533465. The cubic root of 642120245 is about 862.7244789929.

The spelling of 642120245 in words is "six hundred forty-two million, one hundred twenty thousand, two hundred forty-five".