25443121081 has 9 divisors (see below), whose sum is σ = 29598398949. Its totient is φ = 21807432444.

The previous prime is 25443121073. The next prime is 25443121091. The reversal of 25443121081 is 18012134452.

The square root of 25443121081 is 159509.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 25443121081 - 2³ = 25443121073 is a prime.

It is a super-2 number, since 2×25443121081² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25443121031) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1105170 + ... + 1127956.

Almost surely, 2^25443121081 is an apocalyptic number.

25443121081 is the 159509-th square number.

25443121081 is the 79755-th centered octagonal number.

It is an amenable number.

25443121081 is a deficient number, since it is larger than the sum of its proper divisors (4155277868).

25443121081 is an frugal number, since it uses more digits than its factorization.

25443121081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45588 (or 22794 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The spelling of 25443121081 in words is "twenty-five billion, four hundred forty-three million, one hundred twenty-one thousand, eighty-one".