866862421 has 2 divisors, whose sum is σ = 866862422. Its totient is φ = 866862420.

The previous prime is 866862383. The next prime is 866862443. The reversal of 866862421 is 124268668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860542225 + 6320196 = 29335^2 + 2514^2 .

It is a cyclic number.

It is not a de Polignac number, because 866862421 - 2²³ = 858473813 is a prime.

It is a super-3 number, since 3×866862421³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866863421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433431210 + 433431211.

It is an arithmetic number, because the mean of its divisors is an integer number (433431211).

Almost surely, 2^866862421 is an apocalyptic number.

It is an amenable number.

866862421 is a deficient number, since it is larger than the sum of its proper divisors (1).

866862421 is an equidigital number, since it uses as much as digits as its factorization.

866862421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 221184, while the sum is 43.

The square root of 866862421 is about 29442.5274220811. The cubic root of 866862421 is about 953.4912796671.

The spelling of 866862421 in words is "eight hundred sixty-six million, eight hundred sixty-two thousand, four hundred twenty-one".