249181716921 has 8 divisors (see below), whose sum is σ = 336793553760. Its totient is φ = 163845512352.

The previous prime is 249181716887. The next prime is 249181716923. The reversal of 249181716921 is 129617181942.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 249181716921 - 2¹⁸ = 249181454777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (249181716923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 568907811 + ... + 568908248.

It is an arithmetic number, because the mean of its divisors is an integer number (42099194220).

Almost surely, 2^249181716921 is an apocalyptic number.

It is an amenable number.

249181716921 is a deficient number, since it is larger than the sum of its proper divisors (87611836839).

249181716921 is a wasteful number, since it uses less digits than its factorization.

249181716921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1137816135.

The product of its digits is 435456, while the sum is 51.

The spelling of 249181716921 in words is "two hundred forty-nine billion, one hundred eighty-one million, seven hundred sixteen thousand, nine hundred twenty-one".