102778072557 has 4 divisors (see below), whose sum is σ = 137037430080. Its totient is φ = 68518715036.

The previous prime is 102778072549. The next prime is 102778072591. The reversal of 102778072557 is 755270877201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 102778072557 - 2³ = 102778072549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102778072057) 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, 17129678757 + ... + 17129678762.

It is an arithmetic number, because the mean of its divisors is an integer number (34259357520).

Almost surely, 2^102778072557 is an apocalyptic number.

It is an amenable number.

102778072557 is a deficient number, since it is larger than the sum of its proper divisors (34259357523).

102778072557 is an equidigital number, since it uses as much as digits as its factorization.

102778072557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34259357522.

The product of its (nonzero) digits is 1920800, while the sum is 51.

The spelling of 102778072557 in words is "one hundred two billion, seven hundred seventy-eight million, seventy-two thousand, five hundred fifty-seven".