21215210049 has 24 divisors (see below), whose sum is σ = 33497100000. Its totient is φ = 12831906240.

The previous prime is 21215210047. The next prime is 21215210117. The reversal of 21215210049 is 94001251212.

It is not a de Polignac number, because 21215210049 - 2¹ = 21215210047 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21215210041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 165324 + ... + 264125.

It is an arithmetic number, because the mean of its divisors is an integer number (1395712500).

Almost surely, 2^21215210049 is an apocalyptic number.

It is an amenable number.

21215210049 is a deficient number, since it is larger than the sum of its proper divisors (12281889951).

21215210049 is a wasteful number, since it uses less digits than its factorization.

21215210049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429965 (or 429962 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21215210049 in words is "twenty-one billion, two hundred fifteen million, two hundred ten thousand, forty-nine".