2518420781 has 2 divisors, whose sum is σ = 2518420782. Its totient is φ = 2518420780.

The previous prime is 2518420763. The next prime is 2518420831. The reversal of 2518420781 is 1870248152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1547163556 + 971257225 = 39334^2 + 31165^2 .

It is a cyclic number.

It is not a de Polignac number, because 2518420781 - 2¹⁸ = 2518158637 is a prime.

It is a super-2 number, since 2×2518420781² = 12684886460345299922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2518420711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1259210390 + 1259210391.

It is an arithmetic number, because the mean of its divisors is an integer number (1259210391).

Almost surely, 2^2518420781 is an apocalyptic number.

It is an amenable number.

2518420781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2518420781 is an equidigital number, since it uses as much as digits as its factorization.

2518420781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35840, while the sum is 38.

The square root of 2518420781 is about 50183.8697292267. The cubic root of 2518420781 is about 1360.5341005214.

The spelling of 2518420781 in words is "two billion, five hundred eighteen million, four hundred twenty thousand, seven hundred eighty-one".