21699884557 has 16 divisors (see below), whose sum is σ = 24242158080. Its totient is φ = 19294704000.

The previous prime is 21699884539. The next prime is 21699884603. The reversal of 21699884557 is 75548899612.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21699884557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21699884057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215569 + ... + 299782.

It is an arithmetic number, because the mean of its divisors is an integer number (1515134880).

Almost surely, 2^21699884557 is an apocalyptic number.

It is an amenable number.

21699884557 is a deficient number, since it is larger than the sum of its proper divisors (2542273523).

21699884557 is a wasteful number, since it uses less digits than its factorization.

21699884557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515484.

The product of its digits is 43545600, while the sum is 64.

The spelling of 21699884557 in words is "twenty-one billion, six hundred ninety-nine million, eight hundred eighty-four thousand, five hundred fifty-seven".