25012220561 has 8 divisors (see below), whose sum is σ = 25206095784. Its totient is φ = 24818509440.

The previous prime is 25012220537. The next prime is 25012220567. The reversal of 25012220561 is 16502221052.

It can be written as a sum of positive squares in 4 ways, for example, as 639078400 + 24373142161 = 25280^2 + 156119^2 .

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 25012220561 - 2¹⁴ = 25012204177 is a prime.

It is a super-2 number, since 2×25012220561² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25012220561.

It is not an unprimeable number, because it can be changed into a prime (25012220567) 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, 274331 + ... + 353951.

It is an arithmetic number, because the mean of its divisors is an integer number (3150761973).

Almost surely, 2^25012220561 is an apocalyptic number.

It is an amenable number.

25012220561 is a deficient number, since it is larger than the sum of its proper divisors (193875223).

25012220561 is a wasteful number, since it uses less digits than its factorization.

25012220561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82051.

The product of its (nonzero) digits is 2400, while the sum is 26.

The spelling of 25012220561 in words is "twenty-five billion, twelve million, two hundred twenty thousand, five hundred sixty-one".