618747457781 has 4 divisors (see below), whose sum is σ = 618872892972. Its totient is φ = 618622022592.

The previous prime is 618747457703. The next prime is 618747457799. The reversal of 618747457781 is 187754747816.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 113979836881 + 504767620900 = 337609^2 + 710470^2 .

It is a cyclic number.

It is not a de Polignac number, because 618747457781 - 2¹⁴ = 618747441397 is a prime.

It is a super-2 number, since 2×618747457781² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618747450781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62710196 + ... + 62720061.

It is an arithmetic number, because the mean of its divisors is an integer number (154718223243).

Almost surely, 2^618747457781 is an apocalyptic number.

It is an amenable number.

618747457781 is a deficient number, since it is larger than the sum of its proper divisors (125435191).

618747457781 is a wasteful number, since it uses less digits than its factorization.

618747457781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125435190.

The product of its digits is 73758720, while the sum is 65.

The spelling of 618747457781 in words is "six hundred eighteen billion, seven hundred forty-seven million, four hundred fifty-seven thousand, seven hundred eighty-one".