28215430257 has 32 divisors (see below), whose sum is σ = 43723423744. Its totient is φ = 15850209600.

The previous prime is 28215430253. The next prime is 28215430267. The reversal of 28215430257 is 75203451282.

It is not a de Polignac number, because 28215430257 - 2² = 28215430253 is a prime.

It is a super-2 number, since 2×28215430257² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28215430253) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2924832 + ... + 2934462.

It is an arithmetic number, because the mean of its divisors is an integer number (1366356992).

Almost surely, 2^28215430257 is an apocalyptic number.

It is an amenable number.

28215430257 is a deficient number, since it is larger than the sum of its proper divisors (15507993487).

28215430257 is a wasteful number, since it uses less digits than its factorization.

28215430257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11989.

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 28215430257 in words is "twenty-eight billion, two hundred fifteen million, four hundred thirty thousand, two hundred fifty-seven".