21030173457 has 16 divisors (see below), whose sum is σ = 28106558592. Its totient is φ = 13986984960.

The previous prime is 21030173449. The next prime is 21030173467. The reversal of 21030173457 is 75437103012.

It is not a de Polignac number, because 21030173457 - 2³ = 21030173449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21030173467) 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, 3869532 + ... + 3874962.

It is an arithmetic number, because the mean of its divisors is an integer number (1756659912).

Almost surely, 2^21030173457 is an apocalyptic number.

It is an amenable number.

21030173457 is a deficient number, since it is larger than the sum of its proper divisors (7076385135).

21030173457 is a wasteful number, since it uses less digits than its factorization.

21030173457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8248.

The product of its (nonzero) digits is 17640, while the sum is 33.

Adding to 21030173457 its reverse (75437103012), we get a palindrome (96467276469).

The spelling of 21030173457 in words is "twenty-one billion, thirty million, one hundred seventy-three thousand, four hundred fifty-seven".