217620238836 has 144 divisors (see below), whose sum is σ = 693950120640. Its totient is φ = 52176660480.

The previous prime is 217620238769. The next prime is 217620238837. The reversal of 217620238836 is 638832026712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217620238837) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1209981 + ... + 1378148.

It is an arithmetic number, because the mean of its divisors is an integer number (4819098060).

Almost surely, 2^217620238836 is an apocalyptic number.

217620238836 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

217620238836 is an abundant number, since it is smaller than the sum of its proper divisors (476329881804).

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

217620238836 is a wasteful number, since it uses less digits than its factorization.

217620238836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2588174 (or 2588165 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The spelling of 217620238836 in words is "two hundred seventeen billion, six hundred twenty million, two hundred thirty-eight thousand, eight hundred thirty-six".