21240263450126 has 32 divisors (see below), whose sum is σ = 37174755330048. Its totient is φ = 8913589647840.

The previous prime is 21240263450113. The next prime is 21240263450137. The reversal of 21240263450126 is 62105436204212.

It is a super-2 number, since 2×21240263450126² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21240263450126.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55575260 + ... + 55956143.

It is an arithmetic number, because the mean of its divisors is an integer number (1161711104064).

Almost surely, 2^{21240263450126} is an apocalyptic number.

21240263450126 is a deficient number, since it is larger than the sum of its proper divisors (15934491879922).

21240263450126 is a wasteful number, since it uses less digits than its factorization.

21240263450126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111531696.

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 21240263450126 its reverse (62105436204212), we get a palindrome (83345699654338).

The spelling of 21240263450126 in words is "twenty-one trillion, two hundred forty billion, two hundred sixty-three million, four hundred fifty thousand, one hundred twenty-six".