861888551 has 2 divisors, whose sum is σ = 861888552. Its totient is φ = 861888550.

The previous prime is 861888529. The next prime is 861888611. The reversal of 861888551 is 155888168.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 861888551 - 2²² = 857694247 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 861888551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861888751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430944275 + 430944276.

It is an arithmetic number, because the mean of its divisors is an integer number (430944276).

Almost surely, 2^861888551 is an apocalyptic number.

861888551 is a deficient number, since it is larger than the sum of its proper divisors (1).

861888551 is an equidigital number, since it uses as much as digits as its factorization.

861888551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 614400, while the sum is 50.

The square root of 861888551 is about 29357.9384664523. The cubic root of 861888551 is about 951.6641380345.

The spelling of 861888551 in words is "eight hundred sixty-one million, eight hundred eighty-eight thousand, five hundred fifty-one".