86821870 has 16 divisors (see below), whose sum is σ = 156787488. Its totient is φ = 34615840.

The previous prime is 86821837. The next prime is 86821871. The reversal of 86821870 is 7812868.

It is a super-2 number, since 2×86821870² = 15076074220593800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86821871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10849 + ... + 17068.

It is an arithmetic number, because the mean of its divisors is an integer number (9799218).

Almost surely, 2^86821870 is an apocalyptic number.

86821870 is a deficient number, since it is larger than the sum of its proper divisors (69965618).

86821870 is a wasteful number, since it uses less digits than its factorization.

86821870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28235.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 86821870 is about 9317.8253900790. The cubic root of 86821870 is about 442.8021407832.

The spelling of 86821870 in words is "eighty-six million, eight hundred twenty-one thousand, eight hundred seventy".