21599099 has 2 divisors, whose sum is σ = 21599100. Its totient is φ = 21599098.

The previous prime is 21599089. The next prime is 21599107. The reversal of 21599099 is 99099512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21599099 is a prime.

It is a super-2 number, since 2×21599099² = 933042155223602, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21599059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10799549 + 10799550.

It is an arithmetic number, because the mean of its divisors is an integer number (10799550).

Almost surely, 2^21599099 is an apocalyptic number.

21599099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21599099 is an equidigital number, since it uses as much as digits as its factorization.

21599099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65610, while the sum is 44.

The square root of 21599099 is about 4647.4830822715. The cubic root of 21599099 is about 278.4914576745.

The spelling of 21599099 in words is "twenty-one million, five hundred ninety-nine thousand, ninety-nine".