217421807752900 has 27 divisors (see below), whose sum is σ = 471805642795501. Its totient is φ = 86968664120240.

The previous prime is 217421807752847. The next prime is 217421807752931. The reversal of 217421807752900 is 9257708124712.

The square root of 217421807752900 is 14745230.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78271850791044 + 139149956961856 = 8847138^2 + 11796184^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 146715039 + ... + 148189561.

Almost surely, 2^{217421807752900} is an apocalyptic number.

217421807752900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

217421807752900 is the 14745230-th square number.

It is an amenable number.

217421807752900 is an abundant number, since it is smaller than the sum of its proper divisors (254383835042601).

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

217421807752900 is an frugal number, since it uses more digits than its factorization.

217421807752900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2949060 (or 1474530 counting only the distinct ones).

The product of its (nonzero) digits is 3951360, while the sum is 55.

The spelling of 217421807752900 in words is "two hundred seventeen trillion, four hundred twenty-one billion, eight hundred seven million, seven hundred fifty-two thousand, nine hundred".