642655231 has 8 divisors (see below), whose sum is σ = 645800400. Its totient is φ = 639518208.

The previous prime is 642655219. The next prime is 642655243. The reversal of 642655231 is 132556246.

It is an interprime number because it is at equal distance from previous prime (642655219) and next prime (642655243).

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 642655231 - 2¹¹ = 642653183 is a prime.

It is a super-2 number, since 2×642655231² = 826011491863326722, 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 (642655261) 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, 203295 + ... + 206431.

It is an arithmetic number, because the mean of its divisors is an integer number (80725050).

Almost surely, 2^642655231 is an apocalyptic number.

642655231 is a deficient number, since it is larger than the sum of its proper divisors (3145169).

642655231 is a wasteful number, since it uses less digits than its factorization.

642655231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4073.

The product of its digits is 43200, while the sum is 34.

The square root of 642655231 is about 25350.6455736338. The cubic root of 642655231 is about 862.9640070259.

It can be divided in two parts, 64265 and 5231, that added together give a palindrome (69496).

The spelling of 642655231 in words is "six hundred forty-two million, six hundred fifty-five thousand, two hundred thirty-one".