102101010021 has 6 divisors (see below), whose sum is σ = 147479236710. Its totient is φ = 68067340008.

The previous prime is 102101009953. The next prime is 102101010127. The reversal of 102101010021 is 120010101201.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 97437622500 + 4663387521 = 312150^2 + 68289^2 .

It is not a de Polignac number, because 102101010021 - 2⁹ = 102101009509 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 11344556669 = 102101010021 / (1 + 0 + 2 + 1 + 0 + 1 + 0 + 1 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 102101009985 and 102101010012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102101010521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5672278326 + ... + 5672278343.

It is an arithmetic number, because the mean of its divisors is an integer number (24579872785).

Almost surely, 2^102101010021 is an apocalyptic number.

It is an amenable number.

102101010021 is a deficient number, since it is larger than the sum of its proper divisors (45378226689).

102101010021 is a wasteful number, since it uses less digits than its factorization.

102101010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11344556675 (or 11344556672 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 102101010021 its reverse (120010101201), we get a palindrome (222111111222).

The spelling of 102101010021 in words is "one hundred two billion, one hundred one million, ten thousand, twenty-one".