25721506161011 has 16 divisors (see below), whose sum is σ = 25933292666400. Its totient is φ = 25510691162880.

The previous prime is 25721506161007. The next prime is 25721506161023. The reversal of 25721506161011 is 11016160512752.

It is a cyclic number.

It is not a de Polignac number, because 25721506161011 - 2² = 25721506161007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25721506160011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87725225 + ... + 88017941.

It is an arithmetic number, because the mean of its divisors is an integer number (1620830791650).

Almost surely, 2^{25721506161011} is an apocalyptic number.

25721506161011 is a deficient number, since it is larger than the sum of its proper divisors (211786505389).

25721506161011 is a wasteful number, since it uses less digits than its factorization.

25721506161011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294374.

The product of its (nonzero) digits is 25200, while the sum is 38.

Adding to 25721506161011 its reverse (11016160512752), we get a palindrome (36737666673763).

The spelling of 25721506161011 in words is "twenty-five trillion, seven hundred twenty-one billion, five hundred six million, one hundred sixty-one thousand, eleven".