25216046781 has 4 divisors (see below), whose sum is σ = 33621395712. Its totient is φ = 16810697852.

The previous prime is 25216046761. The next prime is 25216046861. The reversal of 25216046781 is 18764061252.

It is a happy number.

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 not a de Polignac number, because 25216046781 - 2⁹ = 25216046269 is a prime.

It is a super-2 number, since 2×25216046781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25216046741) 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, 4202674461 + ... + 4202674466.

It is an arithmetic number, because the mean of its divisors is an integer number (8405348928).

Almost surely, 2^25216046781 is an apocalyptic number.

It is an amenable number.

25216046781 is a deficient number, since it is larger than the sum of its proper divisors (8405348931).

25216046781 is an equidigital number, since it uses as much as digits as its factorization.

25216046781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8405348930.

The product of its (nonzero) digits is 161280, while the sum is 42.

The spelling of 25216046781 in words is "twenty-five billion, two hundred sixteen million, forty-six thousand, seven hundred eighty-one".