861421015 has 32 divisors (see below), whose sum is σ = 1274757120. Its totient is φ = 544178304.

The previous prime is 861421007. The next prime is 861421039. The reversal of 861421015 is 510124168.

It is a cyclic number.

It is not a de Polignac number, because 861421015 - 2³ = 861421007 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 274626 + ... + 277744.

It is an arithmetic number, because the mean of its divisors is an integer number (39836160).

Almost surely, 2^861421015 is an apocalyptic number.

861421015 is a deficient number, since it is larger than the sum of its proper divisors (413336105).

861421015 is a wasteful number, since it uses less digits than its factorization.

861421015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3751.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 861421015 is about 29349.9747018630. The cubic root of 861421015 is about 951.4920284963.

It can be divided in two parts, 8614210 and 15, that added together give a square (8614225 = 2935²).

The spelling of 861421015 in words is "eight hundred sixty-one million, four hundred twenty-one thousand, fifteen".