85724644 has 6 divisors (see below), whose sum is σ = 150018134. Its totient is φ = 42862320.

The previous prime is 85724629. The next prime is 85724647. The reversal of 85724644 is 44642758.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 82591744 + 3132900 = 9088^2 + 1770^2 .

It is a junction number, because it is equal to n+sod(n) for n = 85724597 and 85724606.

It is not an unprimeable number, because it can be changed into a prime (85724647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715577 + ... + 10715584.

Almost surely, 2^85724644 is an apocalyptic number.

It is an amenable number.

85724644 is a deficient number, since it is larger than the sum of its proper divisors (64293490).

85724644 is a wasteful number, since it uses less digits than its factorization.

85724644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21431165 (or 21431163 counting only the distinct ones).

The product of its digits is 215040, while the sum is 40.

The square root of 85724644 is about 9258.7603921907. The cubic root of 85724644 is about 440.9288984734.

It can be divided in two parts, 85724 and 644, that added together give a palindrome (86368).

The spelling of 85724644 in words is "eighty-five million, seven hundred twenty-four thousand, six hundred forty-four".