25217206421 has 8 divisors (see below), whose sum is σ = 27546319488. Its totient is φ = 22894200000.

The previous prime is 25217206381. The next prime is 25217206433. The reversal of 25217206421 is 12460271252.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25217206421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25217206451) 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, 1518020 + ... + 1534541.

It is an arithmetic number, because the mean of its divisors is an integer number (3443289936).

Almost surely, 2^25217206421 is an apocalyptic number.

It is an amenable number.

25217206421 is a deficient number, since it is larger than the sum of its proper divisors (2329113067).

25217206421 is a wasteful number, since it uses less digits than its factorization.

25217206421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3053323.

The product of its (nonzero) digits is 13440, while the sum is 32.

Adding to 25217206421 its reverse (12460271252), we get a palindrome (37677477673).

The spelling of 25217206421 in words is "twenty-five billion, two hundred seventeen million, two hundred six thousand, four hundred twenty-one".