21478596697 has 2 divisors, whose sum is σ = 21478596698. Its totient is φ = 21478596696.

The previous prime is 21478596691. The next prime is 21478596751. The reversal of 21478596697 is 79669587412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18468538201 + 3010058496 = 135899^2 + 54864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21478596697 is a prime.

It is a super-2 number, since 2×21478596697² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21478596691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10739298348 + 10739298349.

It is an arithmetic number, because the mean of its divisors is an integer number (10739298349).

Almost surely, 2^21478596697 is an apocalyptic number.

It is an amenable number.

21478596697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21478596697 is an equidigital number, since it uses as much as digits as its factorization.

21478596697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45722880, while the sum is 64.

The spelling of 21478596697 in words is "twenty-one billion, four hundred seventy-eight million, five hundred ninety-six thousand, six hundred ninety-seven".