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25721791 is a prime number
BaseRepresentation
bin110001000011…
…1101110111111
31210101210122221
41202013232333
523041044131
62315150211
7431426434
oct142075677
953353587
1025721791
1113579187
128745367
1354378c4
1435b7b8b
1523d1411
hex1887bbf

25721791 has 2 divisors, whose sum is σ = 25721792. Its totient is φ = 25721790.

The previous prime is 25721789. The next prime is 25721807. The reversal of 25721791 is 19712752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25721791 - 21 = 25721789 is a prime.

It is a super-2 number, since 2×257217912 = 1323221064495362, which contains 22 as substring.

Together with 25721789, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25721701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12860895 + 12860896.

It is an arithmetic number, because the mean of its divisors is an integer number (12860896).

Almost surely, 225721791 is an apocalyptic number.

25721791 is a deficient number, since it is larger than the sum of its proper divisors (1).

25721791 is an equidigital number, since it uses as much as digits as its factorization.

25721791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 34.

The square root of 25721791 is about 5071.6655055317. The cubic root of 25721791 is about 295.1891576267.

The spelling of 25721791 in words is "twenty-five million, seven hundred twenty-one thousand, seven hundred ninety-one".