20721670126 has 4 divisors (see below), whose sum is σ = 31082505192. Its totient is φ = 10360835062.

The previous prime is 20721670103. The next prime is 20721670127. The reversal of 20721670126 is 62107612702.

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

It is a super-2 number, since 2×20721670126² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20721670091 and 20721670100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20721670127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5180417530 + ... + 5180417533.

It is an arithmetic number, because the mean of its divisors is an integer number (7770626298).

Almost surely, 2^20721670126 is an apocalyptic number.

20721670126 is a deficient number, since it is larger than the sum of its proper divisors (10360835066).

20721670126 is a wasteful number, since it uses less digits than its factorization.

20721670126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10360835065.

The product of its (nonzero) digits is 14112, while the sum is 34.

The spelling of 20721670126 in words is "twenty billion, seven hundred twenty-one million, six hundred seventy thousand, one hundred twenty-six".