861553953 has 48 divisors (see below), whose sum is σ = 1431306240. Its totient is φ = 495331200.

The previous prime is 861553949. The next prime is 861553961. The reversal of 861553953 is 359355168.

861553953 is a `hidden beast` number, since 8 + 6 + 1 + 553 + 95 + 3 = 666.

It is not a de Polignac number, because 861553953 - 2² = 861553949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 861553899 and 861553908.

It is not an unprimeable number, because it can be changed into a prime (861553933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 101088 + ... + 109278.

It is an arithmetic number, because the mean of its divisors is an integer number (29818880).

Almost surely, 2^861553953 is an apocalyptic number.

It is an amenable number.

861553953 is a deficient number, since it is larger than the sum of its proper divisors (569752287).

861553953 is a wasteful number, since it uses less digits than its factorization.

861553953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8270 (or 8267 counting only the distinct ones).

The product of its digits is 486000, while the sum is 45.

The square root of 861553953 is about 29352.2393183212. The cubic root of 861553953 is about 951.5409720206.

The spelling of 861553953 in words is "eight hundred sixty-one million, five hundred fifty-three thousand, nine hundred fifty-three".