625446781 has 2 divisors, whose sum is σ = 625446782. Its totient is φ = 625446780.

The previous prime is 625446737. The next prime is 625446817. The reversal of 625446781 is 187644526.

Together with next prime (625446817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560079556 + 65367225 = 23666^2 + 8085^2 .

It is a cyclic number.

It is not a de Polignac number, because 625446781 - 2¹¹ = 625444733 is a prime.

It is a super-2 number, since 2×625446781² = 782367351726523922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (625446581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312723390 + 312723391.

It is an arithmetic number, because the mean of its divisors is an integer number (312723391).

Almost surely, 2^625446781 is an apocalyptic number.

It is an amenable number.

625446781 is a deficient number, since it is larger than the sum of its proper divisors (1).

625446781 is an equidigital number, since it uses as much as digits as its factorization.

625446781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 322560, while the sum is 43.

The square root of 625446781 is about 25008.9340236644. The cubic root of 625446781 is about 855.1916540826.

It can be divided in two parts, 6254 and 46781, that added together give a palindrome (53035).

The spelling of 625446781 in words is "six hundred twenty-five million, four hundred forty-six thousand, seven hundred eighty-one".