642836381 has 8 divisors (see below), whose sum is σ = 702344928. Its totient is φ = 583506000.

The previous prime is 642836347. The next prime is 642836401. The reversal of 642836381 is 183638246.

It is a happy number.

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

It is not a de Polignac number, because 642836381 - 2¹⁸ = 642574237 is a prime.

It is a super-2 number, since 2×642836381² = 826477225474354322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642833381) 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, 36935 + ... + 51476.

It is an arithmetic number, because the mean of its divisors is an integer number (87793116).

Almost surely, 2^642836381 is an apocalyptic number.

It is an amenable number.

642836381 is a deficient number, since it is larger than the sum of its proper divisors (59508547).

642836381 is a wasteful number, since it uses less digits than its factorization.

642836381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89083.

The product of its digits is 165888, while the sum is 41.

The square root of 642836381 is about 25354.2182092053. The cubic root of 642836381 is about 863.0450827652.

The spelling of 642836381 in words is "six hundred forty-two million, eight hundred thirty-six thousand, three hundred eighty-one".