1647420157 has 2 divisors, whose sum is σ = 1647420158. Its totient is φ = 1647420156.

The previous prime is 1647420121. The next prime is 1647420163. The reversal of 1647420157 is 7510247461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1645600356 + 1819801 = 40566^2 + 1349^2 .

It is an emirp because it is prime and its reverse (7510247461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1647420157 - 2¹⁹ = 1646895869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1647420457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823710078 + 823710079.

It is an arithmetic number, because the mean of its divisors is an integer number (823710079).

Almost surely, 2^1647420157 is an apocalyptic number.

It is an amenable number.

1647420157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1647420157 is an equidigital number, since it uses as much as digits as its factorization.

1647420157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 1647420157 is about 40588.4239285045. The cubic root of 1647420157 is about 1181.0495681804.

The spelling of 1647420157 in words is "one billion, six hundred forty-seven million, four hundred twenty thousand, one hundred fifty-seven".