21011604293 has 4 divisors (see below), whose sum is σ = 21111185568. Its totient is φ = 20912023020.

The previous prime is 21011604287. The next prime is 21011604307. The reversal of 21011604293 is 39240611012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011604293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011604203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49790321 + ... + 49790742.

It is an arithmetic number, because the mean of its divisors is an integer number (5277796392).

Almost surely, 2^21011604293 is an apocalyptic number.

It is an amenable number.

21011604293 is a deficient number, since it is larger than the sum of its proper divisors (99581275).

21011604293 is an equidigital number, since it uses as much as digits as its factorization.

21011604293 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99581274.

The product of its (nonzero) digits is 2592, while the sum is 29.

The spelling of 21011604293 in words is "twenty-one billion, eleven million, six hundred four thousand, two hundred ninety-three".