11651721642 has 64 divisors (see below), whose sum is σ = 28266433920. Its totient is φ = 3528345600.

The previous prime is 11651721607. The next prime is 11651721649. The reversal of 11651721642 is 24612715611.

11651721642 is a `hidden beast` number, since 1 + 1 + 6 + 5 + 1 + 7 + 2 + 1 + 642 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 11651721597 and 11651721606.

It is not an unprimeable number, because it can be changed into a prime (11651721649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 952042 + ... + 964202.

It is an arithmetic number, because the mean of its divisors is an integer number (441663030).

Almost surely, 2^11651721642 is an apocalyptic number.

11651721642 is an abundant number, since it is smaller than the sum of its proper divisors (16614712278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11651721642 is a wasteful number, since it uses less digits than its factorization.

11651721642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13796 (or 13790 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The spelling of 11651721642 in words is "eleven billion, six hundred fifty-one million, seven hundred twenty-one thousand, six hundred forty-two".