642109561254 has 448 divisors, whose sum is σ = 1857351513600. Its totient is φ = 161988885504.

The previous prime is 642109561241. The next prime is 642109561361. The reversal of 642109561254 is 452165901246.

642109561254 is a `hidden beast` number, since 6 + 4 + 21 + 0 + 9 + 5 + 612 + 5 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 359321749 + ... + 359323535.

Almost surely, 2^642109561254 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642109561254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928675756800).

642109561254 is an abundant number, since it is smaller than the sum of its proper divisors (1215241952346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642109561254 is a wasteful number, since it uses less digits than its factorization.

642109561254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1959 (or 1944 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 642109561254 in words is "six hundred forty-two billion, one hundred nine million, five hundred sixty-one thousand, two hundred fifty-four".