21115651107 has 8 divisors (see below), whose sum is σ = 28156027984. Its totient is φ = 14076187488.

The previous prime is 21115651103. The next prime is 21115651157. The reversal of 21115651107 is 70115651112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21115651107 - 2² = 21115651103 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21115651103) 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, 172408 + ... + 268245.

It is an arithmetic number, because the mean of its divisors is an integer number (3519503498).

Almost surely, 2^21115651107 is an apocalyptic number.

21115651107 is a deficient number, since it is larger than the sum of its proper divisors (7040376877).

21115651107 is a wasteful number, since it uses less digits than its factorization.

21115651107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456629.

The product of its (nonzero) digits is 2100, while the sum is 30.

The spelling of 21115651107 in words is "twenty-one billion, one hundred fifteen million, six hundred fifty-one thousand, one hundred seven".