25667921 has 2 divisors, whose sum is σ = 25667922. Its totient is φ = 25667920.

The previous prime is 25667897. The next prime is 25667933. The reversal of 25667921 is 12976652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 7349521 = 4280^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 25667921 - 2¹⁰ = 25666897 is a prime.

It is a super-3 number, since 3×25667921³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25667221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12833960 + 12833961.

It is an arithmetic number, because the mean of its divisors is an integer number (12833961).

Almost surely, 2^25667921 is an apocalyptic number.

It is an amenable number.

25667921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25667921 is an equidigital number, since it uses as much as digits as its factorization.

25667921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 38.

The square root of 25667921 is about 5066.3518432892. The cubic root of 25667921 is about 294.9829387816.

The spelling of 25667921 in words is "twenty-five million, six hundred sixty-seven thousand, nine hundred twenty-one".