25556537 has 2 divisors, whose sum is σ = 25556538. Its totient is φ = 25556536.

The previous prime is 25556533. The next prime is 25556543. The reversal of 25556537 is 73565552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16168441 + 9388096 = 4021^2 + 3064^2 .

It is a cyclic number.

It is not a de Polignac number, because 25556537 - 2² = 25556533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25556537.

It is not a weakly prime, because it can be changed into another prime (25556533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12778268 + 12778269.

It is an arithmetic number, because the mean of its divisors is an integer number (12778269).

Almost surely, 2^25556537 is an apocalyptic number.

It is an amenable number.

25556537 is a deficient number, since it is larger than the sum of its proper divisors (1).

25556537 is an equidigital number, since it uses as much as digits as its factorization.

25556537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157500, while the sum is 38.

The square root of 25556537 is about 5055.3473668977. The cubic root of 25556537 is about 294.5556347226. Note that the first 3 decimals are identical.

The spelling of 25556537 in words is "twenty-five million, five hundred fifty-six thousand, five hundred thirty-seven".