21151040405 has 16 divisors (see below), whose sum is σ = 27710175168. Its totient is φ = 15370608000.

The previous prime is 21151040401. The next prime is 21151040453. The reversal of 21151040405 is 50404015112.

It is not a de Polignac number, because 21151040405 - 2² = 21151040401 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 (21151040401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77936 + ... + 219945.

It is an arithmetic number, because the mean of its divisors is an integer number (1731885948).

Almost surely, 2^21151040405 is an apocalyptic number.

It is an amenable number.

21151040405 is a deficient number, since it is larger than the sum of its proper divisors (6559134763).

21151040405 is a wasteful number, since it uses less digits than its factorization.

21151040405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299188.

The product of its (nonzero) digits is 800, while the sum is 23.

Adding to 21151040405 its reverse (50404015112), we get a palindrome (71555055517).

The spelling of 21151040405 in words is "twenty-one billion, one hundred fifty-one million, forty thousand, four hundred five".