21123102202 has 4 divisors (see below), whose sum is σ = 31684653306. Its totient is φ = 10561551100.

The previous prime is 21123102137. The next prime is 21123102211. The reversal of 21123102202 is 20220132112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14443472761 + 6679629441 = 120181^2 + 81729^2 .

It is a super-2 number, since 2×21123102202² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5280775549 + ... + 5280775552.

Almost surely, 2^21123102202 is an apocalyptic number.

21123102202 is a deficient number, since it is larger than the sum of its proper divisors (10561551104).

21123102202 is a wasteful number, since it uses less digits than its factorization.

21123102202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10561551103.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21123102202 its reverse (20220132112), we get a palindrome (41343234314).

The spelling of 21123102202 in words is "twenty-one billion, one hundred twenty-three million, one hundred two thousand, two hundred two".