249391370881 has 3 divisors (see below), whose sum is σ = 249391870273. Its totient is φ = 249390871490.

The previous prime is 249391370873. The next prime is 249391370903. The reversal of 249391370881 is 188073193942.

It is a happy number.

The square root of 249391370881 is 499391.

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 249391370881 - 2³ = 249391370873 is a prime.

It is a super-2 number, since 2×249391370881² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249391370981) 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, 249696 + ... + 749086.

Almost surely, 2^249391370881 is an apocalyptic number.

249391370881 is the 499391-st square number.

249391370881 is the 249696-th centered octagonal number.

It is an amenable number.

249391370881 is a deficient number, since it is larger than the sum of its proper divisors (499392).

249391370881 is an frugal number, since it uses more digits than its factorization.

249391370881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998782 (or 499391 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 55.

The spelling of 249391370881 in words is "two hundred forty-nine billion, three hundred ninety-one million, three hundred seventy thousand, eight hundred eighty-one".