28139707 has 2 divisors, whose sum is σ = 28139708. Its totient is φ = 28139706.

The previous prime is 28139689. The next prime is 28139719. The reversal of 28139707 is 70793182.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28139707 is a prime.

It is a super-2 number, since 2×28139707² = 1583686220091698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28139747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14069853 + 14069854.

It is an arithmetic number, because the mean of its divisors is an integer number (14069854).

Almost surely, 2^28139707 is an apocalyptic number.

28139707 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139707 is an equidigital number, since it uses as much as digits as its factorization.

28139707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 28139707 is about 5304.6872669367. The cubic root of 28139707 is about 304.1630985090.

The spelling of 28139707 in words is "twenty-eight million, one hundred thirty-nine thousand, seven hundred seven".