21111345672 has 32 divisors (see below), whose sum is σ = 53271626400. Its totient is φ = 6971346944.

The previous prime is 21111345667. The next prime is 21111345677. The reversal of 21111345672 is 27654311112.

It is an interprime number because it is at equal distance from previous prime (21111345667) and next prime (21111345677).

It is not an unprimeable number, because it can be changed into a prime (21111345677) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4107897 + ... + 4113032.

It is an arithmetic number, because the mean of its divisors is an integer number (1664738325).

Almost surely, 2^21111345672 is an apocalyptic number.

It is an amenable number.

21111345672 is an abundant number, since it is smaller than the sum of its proper divisors (32160280728).

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

21111345672 is a wasteful number, since it uses less digits than its factorization.

21111345672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8221045 (or 8221041 counting only the distinct ones).

The product of its digits is 10080, while the sum is 33.

Adding to 21111345672 its reverse (27654311112), we get a palindrome (48765656784).

The spelling of 21111345672 in words is "twenty-one billion, one hundred eleven million, three hundred forty-five thousand, six hundred seventy-two".