21031947235 has 16 divisors (see below), whose sum is σ = 27225172800. Its totient is φ = 15505326720.

The previous prime is 21031947187. The next prime is 21031947263. The reversal of 21031947235 is 53274913012.

It is a de Polignac number, because none of the positive numbers 2^k-21031947235 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21031947194 and 21031947203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231156 + ... + 309025.

It is an arithmetic number, because the mean of its divisors is an integer number (1701573300).

Almost surely, 2^21031947235 is an apocalyptic number.

21031947235 is a deficient number, since it is larger than the sum of its proper divisors (6193225565).

21031947235 is a wasteful number, since it uses less digits than its factorization.

21031947235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540798.

The product of its (nonzero) digits is 45360, while the sum is 37.

The spelling of 21031947235 in words is "twenty-one billion, thirty-one million, nine hundred forty-seven thousand, two hundred thirty-five".