1605251251 has 2 divisors, whose sum is σ = 1605251252. Its totient is φ = 1605251250.

The previous prime is 1605251201. The next prime is 1605251267. The reversal of 1605251251 is 1521525061.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1605251251 - 2²³ = 1596862643 is a prime.

It is not a weakly prime, because it can be changed into another prime (1605251201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802625625 + 802625626.

It is an arithmetic number, because the mean of its divisors is an integer number (802625626).

Almost surely, 2^1605251251 is an apocalyptic number.

1605251251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605251251 is an equidigital number, since it uses as much as digits as its factorization.

1605251251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3000, while the sum is 28.

The square root of 1605251251 is about 40065.5868670359. The cubic root of 1605251251 is about 1170.8852605663.

The spelling of 1605251251 in words is "one billion, six hundred five million, two hundred fifty-one thousand, two hundred fifty-one".