249692221 has 4 divisors (see below), whose sum is σ = 251187552. Its totient is φ = 248196892.

The previous prime is 249692207. The next prime is 249692239. The reversal of 249692221 is 122296942.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122296942 = 2 ⋅61148471.

It is a cyclic number.

It is not a de Polignac number, because 249692221 - 2¹⁷ = 249561149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249692251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 747415 + ... + 747748.

It is an arithmetic number, because the mean of its divisors is an integer number (62796888).

Almost surely, 2^249692221 is an apocalyptic number.

It is an amenable number.

249692221 is a deficient number, since it is larger than the sum of its proper divisors (1495331).

249692221 is a wasteful number, since it uses less digits than its factorization.

249692221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495330.

The product of its digits is 31104, while the sum is 37.

The square root of 249692221 is about 15801.6524768772. The cubic root of 249692221 is about 629.7019006257.

The spelling of 249692221 in words is "two hundred forty-nine million, six hundred ninety-two thousand, two hundred twenty-one".