28691019 has 72 divisors (see below), whose sum is σ = 52818480. Its totient is φ = 14902272.

The previous prime is 28691017. The next prime is 28691059. The reversal of 28691019 is 91019682.

It is not a de Polignac number, because 28691019 - 2¹ = 28691017 is a prime.

It is a super-2 number, since 2×28691019² = 1646349142516722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28691017) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 322327 + ... + 322415.

It is an arithmetic number, because the mean of its divisors is an integer number (733590).

Almost surely, 2^28691019 is an apocalyptic number.

28691019 is a deficient number, since it is larger than the sum of its proper divisors (24127461).

28691019 is a wasteful number, since it uses less digits than its factorization.

28691019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 28691019 is about 5356.3998170413. The cubic root of 28691019 is about 306.1366492077.

The spelling of 28691019 in words is "twenty-eight million, six hundred ninety-one thousand, nineteen".