642541391 has 8 divisors (see below), whose sum is σ = 652537824. Its totient is φ = 632620800.

The previous prime is 642541379. The next prime is 642541421. The reversal of 642541391 is 193145246.

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 642541391 - 2⁶ = 642541327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642541321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1766 + ... + 35891.

It is an arithmetic number, because the mean of its divisors is an integer number (81567228).

Almost surely, 2^642541391 is an apocalyptic number.

642541391 is a deficient number, since it is larger than the sum of its proper divisors (9996433).

642541391 is a wasteful number, since it uses less digits than its factorization.

642541391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37921.

The product of its digits is 25920, while the sum is 35.

The square root of 642541391 is about 25348.4001664799. The cubic root of 642541391 is about 862.9130488454.

The spelling of 642541391 in words is "six hundred forty-two million, five hundred forty-one thousand, three hundred ninety-one".