21315049 has 8 divisors (see below), whose sum is σ = 24857600. Its totient is φ = 18269748.

The previous prime is 21315037. The next prime is 21315053. The reversal of 21315049 is 94051312.

It is not a de Polignac number, because 21315049 - 2¹¹ = 21313001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21315079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30729 + ... + 31414.

It is an arithmetic number, because the mean of its divisors is an integer number (3107200).

Almost surely, 2^21315049 is an apocalyptic number.

It is an amenable number.

21315049 is a deficient number, since it is larger than the sum of its proper divisors (3542551).

21315049 is an frugal number, since it uses more digits than its factorization.

21315049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62164 (or 62150 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21315049 is about 4616.8223920788. The cubic root of 21315049 is about 277.2652517884.

The spelling of 21315049 in words is "twenty-one million, three hundred fifteen thousand, forty-nine".