21510052011 has 32 divisors (see below), whose sum is σ = 36444364800. Its totient is φ = 12282943680.

The previous prime is 21510052001. The next prime is 21510052049. The reversal of 21510052011 is 11025001512.

It is not a de Polignac number, because 21510052011 - 2¹⁵ = 21510019243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21510052001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 239335 + ... + 316703.

It is an arithmetic number, because the mean of its divisors is an integer number (1138886400).

Almost surely, 2^21510052011 is an apocalyptic number.

21510052011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21510052011 is a deficient number, since it is larger than the sum of its proper divisors (14934312789).

21510052011 is a wasteful number, since it uses less digits than its factorization.

21510052011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78856 (or 78850 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

Adding to 21510052011 its reverse (11025001512), we get a palindrome (32535053523).

The spelling of 21510052011 in words is "twenty-one billion, five hundred ten million, fifty-two thousand, eleven".