209792197251 has 48 divisors (see below), whose sum is σ = 373047030720. Its totient is φ = 110634958080.

The previous prime is 209792197231. The next prime is 209792197283. The reversal of 209792197251 is 152791297902.

It is not a de Polignac number, because 209792197251 - 2⁷ = 209792197123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209792197231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3994381 + ... + 4046561.

It is an arithmetic number, because the mean of its divisors is an integer number (7771813140).

Almost surely, 2^209792197251 is an apocalyptic number.

209792197251 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

209792197251 is a deficient number, since it is larger than the sum of its proper divisors (163254833469).

209792197251 is a wasteful number, since it uses less digits than its factorization.

209792197251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57116 (or 57113 counting only the distinct ones).

The product of its (nonzero) digits is 1428840, while the sum is 54.

The spelling of 209792197251 in words is "two hundred nine billion, seven hundred ninety-two million, one hundred ninety-seven thousand, two hundred fifty-one".