102691861 has 2 divisors, whose sum is σ = 102691862. Its totient is φ = 102691860.

The previous prime is 102691837. The next prime is 102691873. The reversal of 102691861 is 168196201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55219761 + 47472100 = 7431^2 + 6890^2 .

It is a cyclic number.

It is not a de Polignac number, because 102691861 - 2¹⁵ = 102659093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102691811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51345930 + 51345931.

It is an arithmetic number, because the mean of its divisors is an integer number (51345931).

Almost surely, 2^102691861 is an apocalyptic number.

It is an amenable number.

102691861 is a deficient number, since it is larger than the sum of its proper divisors (1).

102691861 is an equidigital number, since it uses as much as digits as its factorization.

102691861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 102691861 is about 10133.6992751907. The cubic root of 102691861 is about 468.2868991702.

The spelling of 102691861 in words is "one hundred two million, six hundred ninety-one thousand, eight hundred sixty-one".