21235731406 has 16 divisors (see below), whose sum is σ = 33535046160. Its totient is φ = 10057547520.

The previous prime is 21235731401. The next prime is 21235731457. The reversal of 21235731406 is 60413753212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235731401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245896 + ... + 320836.

It is an arithmetic number, because the mean of its divisors is an integer number (2095940385).

Almost surely, 2^21235731406 is an apocalyptic number.

21235731406 is a deficient number, since it is larger than the sum of its proper divisors (12299314754).

21235731406 is a wasteful number, since it uses less digits than its factorization.

21235731406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82419.

The product of its (nonzero) digits is 30240, while the sum is 34.

The spelling of 21235731406 in words is "twenty-one billion, two hundred thirty-five million, seven hundred thirty-one thousand, four hundred six".