21510223073434 has 4 divisors (see below), whose sum is σ = 32265334610154. Its totient is φ = 10755111536716.

The previous prime is 21510223073419. The next prime is 21510223073441. The reversal of 21510223073434 is 43437032201512.

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., 16285784869225 + 5224438204209 = 4035565^2 + 2285703^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21510223073393 and 21510223073402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5377555768357 + ... + 5377555768360.

Almost surely, 2^{21510223073434} is an apocalyptic number.

21510223073434 is a deficient number, since it is larger than the sum of its proper divisors (10755111536720).

21510223073434 is a wasteful number, since it uses less digits than its factorization.

21510223073434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10755111536719.

The product of its (nonzero) digits is 120960, while the sum is 37.

Adding to 21510223073434 its reverse (43437032201512), we get a palindrome (64947255274946).

The spelling of 21510223073434 in words is "twenty-one trillion, five hundred ten billion, two hundred twenty-three million, seventy-three thousand, four hundred thirty-four".