253362721 has 4 divisors (see below), whose sum is σ = 261535744. Its totient is φ = 245189700.

The previous prime is 253362691. The next prime is 253362727. The reversal of 253362721 is 127263352.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-253362721 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 8172991 = 253362721 / (2 + 5 + 3 + 3 + 6 + 2 + 7 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (253362727) 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, 4086465 + ... + 4086526.

It is an arithmetic number, because the mean of its divisors is an integer number (65383936).

Almost surely, 2^253362721 is an apocalyptic number.

It is an amenable number.

253362721 is a deficient number, since it is larger than the sum of its proper divisors (8173023).

253362721 is an equidigital number, since it uses as much as digits as its factorization.

253362721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8173022.

The product of its digits is 15120, while the sum is 31.

The square root of 253362721 is about 15917.3716737406. The cubic root of 253362721 is about 632.7724633444.

The spelling of 253362721 in words is "two hundred fifty-three million, three hundred sixty-two thousand, seven hundred twenty-one".