21536222001 has 16 divisors (see below), whose sum is σ = 32819432448. Its totient is φ = 12305538000.

The previous prime is 21536221991. The next prime is 21536222003. The reversal of 21536222001 is 10022263512.

It is not a de Polignac number, because 21536222001 - 2¹⁷ = 21536090929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21536222003) 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, 373156 + ... + 426986.

It is an arithmetic number, because the mean of its divisors is an integer number (2051214528).

Almost surely, 2^21536222001 is an apocalyptic number.

21536222001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21536222001 is a deficient number, since it is larger than the sum of its proper divisors (11283210447).

21536222001 is a wasteful number, since it uses less digits than its factorization.

21536222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72892.

The product of its (nonzero) digits is 1440, while the sum is 24.

Adding to 21536222001 its reverse (10022263512), we get a palindrome (31558485513).

The spelling of 21536222001 in words is "twenty-one billion, five hundred thirty-six million, two hundred twenty-two thousand, one".