209231451577225 has 81 divisors (see below), whose sum is σ = 331745666848743. Its totient is φ = 130426524228000.

The previous prime is 209231451577199. The next prime is 209231451577249. The reversal of 209231451577225 is 522775154132902.

The square root of 209231451577225 is 14464835.

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., 75323322567801 + 133908129009424 = 8678901^2 + 11571868^2 .

It is not a de Polignac number, because 209231451577225 - 2¹¹ = 209231451575177 is a prime.

It is a super-2 number, since 2×209231451577225² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 5568942690 + ... + 5568980260.

Almost surely, 2^{209231451577225} is an apocalyptic number.

209231451577225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

209231451577225 is the 14464835-th square number.

209231451577225 is the 7232418-th centered octagonal number.

It is an amenable number.

209231451577225 is a deficient number, since it is larger than the sum of its proper divisors (122514215271518).

209231451577225 is an frugal number, since it uses more digits than its factorization.

209231451577225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75188 (or 37594 counting only the distinct ones).

The product of its (nonzero) digits is 10584000, while the sum is 55.

The spelling of 209231451577225 in words is "two hundred nine trillion, two hundred thirty-one billion, four hundred fifty-one million, five hundred seventy-seven thousand, two hundred twenty-five".