68490553849 has 3 divisors (see below), whose sum is σ = 68490815557. Its totient is φ = 68490292142.

The previous prime is 68490553847. The next prime is 68490553871. The reversal of 68490553849 is 94835509486.

The square root of 68490553849 is 261707.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 68490553849 - 2¹ = 68490553847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68490553843) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 130854 + ... + 392560.

Almost surely, 2^68490553849 is an apocalyptic number.

68490553849 is the 261707-th square number.

68490553849 is the 130854-th centered octagonal number.

It is an amenable number.

68490553849 is a deficient number, since it is larger than the sum of its proper divisors (261708).

68490553849 is an frugal number, since it uses more digits than its factorization.

68490553849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523414 (or 261707 counting only the distinct ones).

The product of its (nonzero) digits is 37324800, while the sum is 61.

The spelling of 68490553849 in words is "sixty-eight billion, four hundred ninety million, five hundred fifty-three thousand, eight hundred forty-nine".