21695750078 has 4 divisors (see below), whose sum is σ = 32543625120. Its totient is φ = 10847875038.

The previous prime is 21695750071. The next prime is 21695750099. The reversal of 21695750078 is 87005759612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21695750071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5423937518 + ... + 5423937521.

It is an arithmetic number, because the mean of its divisors is an integer number (8135906280).

Almost surely, 2^21695750078 is an apocalyptic number.

21695750078 is a deficient number, since it is larger than the sum of its proper divisors (10847875042).

21695750078 is a wasteful number, since it uses less digits than its factorization.

21695750078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10847875041.

The product of its (nonzero) digits is 1058400, while the sum is 50.

The spelling of 21695750078 in words is "twenty-one billion, six hundred ninety-five million, seven hundred fifty thousand, seventy-eight".