9999613972 has 6 divisors (see below), whose sum is σ = 17499324458. Its totient is φ = 4999806984.

The previous prime is 9999613951. The next prime is 9999613973. The reversal of 9999613972 is 2793169999.

It can be written as a sum of positive squares in only one way, i.e., 5110248196 + 4889365776 = 71486^2 + 69924^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999613973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1249951743 + ... + 1249951750.

Almost surely, 2^9999613972 is an apocalyptic number.

It is an amenable number.

9999613972 is a deficient number, since it is larger than the sum of its proper divisors (7499710486).

9999613972 is a wasteful number, since it uses less digits than its factorization.

9999613972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2499903497 (or 2499903495 counting only the distinct ones).

The product of its digits is 14880348, while the sum is 64.

The square root of 9999613972 is about 99998.0698413724. The cubic root of 9999613972 is about 2154.4069672713.

The spelling of 9999613972 in words is "nine billion, nine hundred ninety-nine million, six hundred thirteen thousand, nine hundred seventy-two".