21730352397 has 16 divisors (see below), whose sum is σ = 31791287808. Its totient is φ = 13120211520.

The previous prime is 21730352387. The next prime is 21730352411. The reversal of 21730352397 is 79325303712.

It is not a de Polignac number, because 21730352397 - 2¹⁰ = 21730351373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21730352327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5254429 + ... + 5258562.

It is an arithmetic number, because the mean of its divisors is an integer number (1986955488).

Almost surely, 2^21730352397 is an apocalyptic number.

It is an amenable number.

21730352397 is a deficient number, since it is larger than the sum of its proper divisors (10060935411).

21730352397 is a wasteful number, since it uses less digits than its factorization.

21730352397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10513060.

The product of its (nonzero) digits is 238140, while the sum is 42.

The spelling of 21730352397 in words is "twenty-one billion, seven hundred thirty million, three hundred fifty-two thousand, three hundred ninety-seven".