25221736661 has 8 divisors (see below), whose sum is σ = 27542795904. Its totient is φ = 22905373120.

The previous prime is 25221736651. The next prime is 25221736663. The reversal of 25221736661 is 16663712252.

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 25221736661 - 2⁶ = 25221736597 is a prime.

It is a super-3 number, since 3×25221736661³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25221736663) 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, 1162685 + ... + 1184178.

It is an arithmetic number, because the mean of its divisors is an integer number (3442849488).

Almost surely, 2^25221736661 is an apocalyptic number.

It is an amenable number.

25221736661 is a deficient number, since it is larger than the sum of its proper divisors (2321059243).

25221736661 is a wasteful number, since it uses less digits than its factorization.

25221736661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2347851.

The product of its digits is 181440, while the sum is 41.

The spelling of 25221736661 in words is "twenty-five billion, two hundred twenty-one million, seven hundred thirty-six thousand, six hundred sixty-one".