64890031 has 4 divisors (see below), whose sum is σ = 65953864. Its totient is φ = 63826200.

The previous prime is 64890019. The next prime is 64890079. The reversal of 64890031 is 13009846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13009846 = 2 ⋅6504923.

It is a cyclic number.

It is not a de Polignac number, because 64890031 - 2²¹ = 62792879 is a prime.

It is a super-2 number, since 2×64890031² = 8421432246361922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64889975 and 64890002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64890011) 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, 531825 + ... + 531946.

It is an arithmetic number, because the mean of its divisors is an integer number (16488466).

Almost surely, 2^64890031 is an apocalyptic number.

64890031 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

64890031 is the 3603-rd centered decagonal number.

64890031 is a deficient number, since it is larger than the sum of its proper divisors (1063833).

64890031 is a wasteful number, since it uses less digits than its factorization.

64890031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063832.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 64890031 is about 8055.4348734255. The cubic root of 64890031 is about 401.8457016147.

Adding to 64890031 its reverse (13009846), we get a palindrome (77899877).

The spelling of 64890031 in words is "sixty-four million, eight hundred ninety thousand, thirty-one".