102055781 has 4 divisors (see below), whose sum is σ = 103785600. Its totient is φ = 100325964.

The previous prime is 102055771. The next prime is 102055801. The reversal of 102055781 is 187550201.

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 a de Polignac number, because none of the positive numbers 2^k-102055781 is a prime.

It is a super-2 number, since 2×102055781² = 20830764871039922, which 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 (102055711) 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, 864821 + ... + 864938.

It is an arithmetic number, because the mean of its divisors is an integer number (25946400).

Almost surely, 2^102055781 is an apocalyptic number.

It is an amenable number.

102055781 is a deficient number, since it is larger than the sum of its proper divisors (1729819).

102055781 is an equidigital number, since it uses as much as digits as its factorization.

102055781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1729818.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 102055781 is about 10102.2661319132. The cubic root of 102055781 is about 467.3180295915.

The spelling of 102055781 in words is "one hundred two million, fifty-five thousand, seven hundred eighty-one".