21541402511 has 4 divisors (see below), whose sum is σ = 21999730272. Its totient is φ = 21083074752.

The previous prime is 21541402469. The next prime is 21541402529. The reversal of 21541402511 is 11520414512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21541402511 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 (21541402591) 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, 229163810 + ... + 229163903.

It is an arithmetic number, because the mean of its divisors is an integer number (5499932568).

Almost surely, 2^21541402511 is an apocalyptic number.

21541402511 is a deficient number, since it is larger than the sum of its proper divisors (458327761).

21541402511 is an equidigital number, since it uses as much as digits as its factorization.

21541402511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458327760.

The product of its (nonzero) digits is 1600, while the sum is 26.

The spelling of 21541402511 in words is "twenty-one billion, five hundred forty-one million, four hundred two thousand, five hundred eleven".