28471631 has 4 divisors (see below), whose sum is σ = 29709552. Its totient is φ = 27233712.

The previous prime is 28471621. The next prime is 28471643. The reversal of 28471631 is 13617482.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28471631 - 2¹⁸ = 28209487 is a prime.

It is a super-2 number, since 2×28471631² = 1621267543600322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28471601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 618926 + ... + 618971.

It is an arithmetic number, because the mean of its divisors is an integer number (7427388).

Almost surely, 2^28471631 is an apocalyptic number.

28471631 is a deficient number, since it is larger than the sum of its proper divisors (1237921).

28471631 is a wasteful number, since it uses less digits than its factorization.

28471631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237920.

The product of its digits is 8064, while the sum is 32.

The square root of 28471631 is about 5335.8814642006. The cubic root of 28471631 is about 305.3543529968.

The spelling of 28471631 in words is "twenty-eight million, four hundred seventy-one thousand, six hundred thirty-one".