21151718698 has 64 divisors (see below), whose sum is σ = 36332706816. Its totient is φ = 9150768000.

The previous prime is 21151718647. The next prime is 21151718723. The reversal of 21151718698 is 89681715112.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6464803 + ... + 6468073.

It is an arithmetic number, because the mean of its divisors is an integer number (567698544).

Almost surely, 2^21151718698 is an apocalyptic number.

21151718698 is a deficient number, since it is larger than the sum of its proper divisors (15180988118).

21151718698 is a wasteful number, since it uses less digits than its factorization.

21151718698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3499.

The product of its digits is 241920, while the sum is 49.

The spelling of 21151718698 in words is "twenty-one billion, one hundred fifty-one million, seven hundred eighteen thousand, six hundred ninety-eight".