1025399491 has 2 divisors, whose sum is σ = 1025399492. Its totient is φ = 1025399490.

The previous prime is 1025399471. The next prime is 1025399503. The reversal of 1025399491 is 1949935201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1025399491 - 2¹³ = 1025391299 is a prime.

It is a super-2 number, since 2×1025399491² = 2102888232286118162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1025399461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 512699745 + 512699746.

It is an arithmetic number, because the mean of its divisors is an integer number (512699746).

Almost surely, 2^1025399491 is an apocalyptic number.

1025399491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1025399491 is an equidigital number, since it uses as much as digits as its factorization.

1025399491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 1025399491 is about 32021.8595806052. The cubic root of 1025399491 is about 1008.3958101003.

The spelling of 1025399491 in words is "one billion, twenty-five million, three hundred ninety-nine thousand, four hundred ninety-one".