1240520420551 has 2 divisors, whose sum is σ = 1240520420552. Its totient is φ = 1240520420550.

The previous prime is 1240520420539. The next prime is 1240520420609. The reversal of 1240520420551 is 1550240250421.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1240520420551 - 2⁹ = 1240520420039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1240520420651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620260210275 + 620260210276.

It is an arithmetic number, because the mean of its divisors is an integer number (620260210276).

Almost surely, 2^{1240520420551} is an apocalyptic number.

1240520420551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240520420551 is an equidigital number, since it uses as much as digits as its factorization.

1240520420551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16000, while the sum is 31.

Adding to 1240520420551 its reverse (1550240250421), we get a palindrome (2790760670972).

The spelling of 1240520420551 in words is "one trillion, two hundred forty billion, five hundred twenty million, four hundred twenty thousand, five hundred fifty-one".