21971587603 has 6 divisors (see below), whose sum is σ = 25558785636. Its totient is φ = 18832789332.

The previous prime is 21971587577. The next prime is 21971587607. The reversal of 21971587603 is 30678517912.

It is a happy number.

It is not a de Polignac number, because 21971587603 - 2²⁵ = 21938033171 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 448399747 = 21971587603 / (2 + 1 + 9 + 7 + 1 + 5 + 8 + 7 + 6 + 0 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21971587607) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 224199825 + ... + 224199922.

It is an arithmetic number, because the mean of its divisors is an integer number (4259797606).

Almost surely, 2^21971587603 is an apocalyptic number.

21971587603 is a deficient number, since it is larger than the sum of its proper divisors (3587198033).

21971587603 is an equidigital number, since it uses as much as digits as its factorization.

21971587603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448399761 (or 448399754 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 49.

The spelling of 21971587603 in words is "twenty-one billion, nine hundred seventy-one million, five hundred eighty-seven thousand, six hundred three".