1864516021 has 8 divisors (see below), whose sum is σ = 1982389464. Its totient is φ = 1747553280.

The previous prime is 1864516013. The next prime is 1864516033. The reversal of 1864516021 is 1206154681.

It can be written as a sum of positive squares in 4 ways, for example, as 306635121 + 1557880900 = 17511^2 + 39470^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1864516021 - 2³ = 1864516013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1864516001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223450 + ... + 231643.

It is an arithmetic number, because the mean of its divisors is an integer number (247798683).

Almost surely, 2^1864516021 is an apocalyptic number.

It is an amenable number.

1864516021 is a deficient number, since it is larger than the sum of its proper divisors (117873443).

1864516021 is a wasteful number, since it uses less digits than its factorization.

1864516021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455351.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 1864516021 is about 43180.0419291135. The cubic root of 1864516021 is about 1230.8034543906.

The spelling of 1864516021 in words is "one billion, eight hundred sixty-four million, five hundred sixteen thousand, twenty-one".