21534956149 has 12 divisors (see below), whose sum is σ = 25352689824. Its totient is φ = 18236138424.

The previous prime is 21534956123. The next prime is 21534956161. The reversal of 21534956149 is 94165943512.

It is a de Polignac number, because none of the positive numbers 2^k-21534956149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21534356149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2643457 + ... + 2651590.

It is an arithmetic number, because the mean of its divisors is an integer number (2112724152).

Almost surely, 2^21534956149 is an apocalyptic number.

It is an amenable number.

21534956149 is a deficient number, since it is larger than the sum of its proper divisors (3817733675).

21534956149 is an equidigital number, since it uses as much as digits as its factorization.

21534956149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5295144 (or 5295137 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 49.

The spelling of 21534956149 in words is "twenty-one billion, five hundred thirty-four million, nine hundred fifty-six thousand, one hundred forty-nine".