21121102101021 has 48 divisors (see below), whose sum is σ = 30602491587072. Its totient is φ = 12951589996800.

The previous prime is 21121102101017. The next prime is 21121102101103. The reversal of 21121102101021 is 12010120112112.

It is a happy number.

It is not a de Polignac number, because 21121102101021 - 2² = 21121102101017 is a prime.

It is a super-2 number, since 2×21121102101021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121102101521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 184147431 + ... + 184262091.

It is an arithmetic number, because the mean of its divisors is an integer number (637551908064).

Almost surely, 2^{21121102101021} is an apocalyptic number.

It is an amenable number.

21121102101021 is a deficient number, since it is larger than the sum of its proper divisors (9481389486051).

21121102101021 is a wasteful number, since it uses less digits than its factorization.

21121102101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115974 (or 115961 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21121102101021 its reverse (12010120112112), we get a palindrome (33131222213133).

The spelling of 21121102101021 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred two million, one hundred one thousand, twenty-one".