21459015697 has 16 divisors (see below), whose sum is σ = 25996947840. Its totient is φ = 17291651328.

The previous prime is 21459015691. The next prime is 21459015727. The reversal of 21459015697 is 79651095412.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21459015697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21459015697.

It is not an unprimeable number, because it can be changed into a prime (21459015691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1554 + ... + 207172.

It is an arithmetic number, because the mean of its divisors is an integer number (1624809240).

Almost surely, 2^21459015697 is an apocalyptic number.

It is an amenable number.

21459015697 is a deficient number, since it is larger than the sum of its proper divisors (4537932143).

21459015697 is a wasteful number, since it uses less digits than its factorization.

21459015697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206520.

The product of its (nonzero) digits is 680400, while the sum is 49.

The spelling of 21459015697 in words is "twenty-one billion, four hundred fifty-nine million, fifteen thousand, six hundred ninety-seven".