21121061610 has 32 divisors (see below), whose sum is σ = 55298780352. Its totient is φ = 5120257280.

The previous prime is 21121061587. The next prime is 21121061617. The reversal of 21121061610 is 1616012112.

It is not an unprimeable number, because it can be changed into a prime (21121061617) 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, 32001279 + ... + 32001938.

It is an arithmetic number, because the mean of its divisors is an integer number (1728086886).

Almost surely, 2^21121061610 is an apocalyptic number.

21121061610 is an abundant number, since it is smaller than the sum of its proper divisors (34177718742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121061610 is a wasteful number, since it uses less digits than its factorization.

21121061610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64003238.

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 21121061610 its reverse (1616012112), we get a palindrome (22737073722).

The spelling of 21121061610 in words is "twenty-one billion, one hundred twenty-one million, sixty-one thousand, six hundred ten".