21761949051 has 16 divisors (see below), whose sum is σ = 32242281120. Its totient is φ = 14506905600.

The previous prime is 21761949047. The next prime is 21761949133. The reversal of 21761949051 is 15094916712.

21761949051 is a `hidden beast` number, since 21 + 7 + 619 + 4 + 9 + 0 + 5 + 1 = 666.

It is not a de Polignac number, because 21761949051 - 2² = 21761949047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21761948988 and 21761949006.

It is not an unprimeable number, because it can be changed into a prime (21761949151) 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, 564571 + ... + 601883.

It is an arithmetic number, because the mean of its divisors is an integer number (2015142570).

Almost surely, 2^21761949051 is an apocalyptic number.

21761949051 is a deficient number, since it is larger than the sum of its proper divisors (10480332069).

21761949051 is a wasteful number, since it uses less digits than its factorization.

21761949051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58923 (or 58917 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 21761949051 in words is "twenty-one billion, seven hundred sixty-one million, nine hundred forty-nine thousand, fifty-one".