25347661921 has 8 divisors (see below), whose sum is σ = 25500979944. Its totient is φ = 25194422400.

The previous prime is 25347661919. The next prime is 25347661931. The reversal of 25347661921 is 12916674352.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5915301921 + 19432360000 = 76911^2 + 139400^2 .

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 25347661921 - 2¹ = 25347661919 is a prime.

It is a super-2 number, since 2×25347661921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25347661931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 709335 + ... + 744211.

It is an arithmetic number, because the mean of its divisors is an integer number (3187622493).

Almost surely, 2^25347661921 is an apocalyptic number.

It is an amenable number.

25347661921 is a deficient number, since it is larger than the sum of its proper divisors (153318023).

25347661921 is a wasteful number, since it uses less digits than its factorization.

25347661921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39251.

The product of its digits is 544320, while the sum is 46.

The spelling of 25347661921 in words is "twenty-five billion, three hundred forty-seven million, six hundred sixty-one thousand, nine hundred twenty-one".