25210161605 has 8 divisors (see below), whose sum is σ = 30291538200. Its totient is φ = 20141899776.

The previous prime is 25210161601. The next prime is 25210161617. The reversal of 25210161605 is 50616101252.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4713371716 + 20496789889 = 68654^2 + 143167^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 25210161605 - 2² = 25210161601 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25210161601) 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, 3274460 + ... + 3282149.

It is an arithmetic number, because the mean of its divisors is an integer number (3786442275).

Almost surely, 2^25210161605 is an apocalyptic number.

It is an amenable number.

25210161605 is a deficient number, since it is larger than the sum of its proper divisors (5081376595).

25210161605 is an equidigital number, since it uses as much as digits as its factorization.

25210161605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6557383.

The product of its (nonzero) digits is 3600, while the sum is 29.

Adding to 25210161605 its reverse (50616101252), we get a palindrome (75826262857).

The spelling of 25210161605 in words is "twenty-five billion, two hundred ten million, one hundred sixty-one thousand, six hundred five".