1630537621 has 4 divisors (see below), whose sum is σ = 1631320992. Its totient is φ = 1629754252.

The previous prime is 1630537613. The next prime is 1630537759. The reversal of 1630537621 is 1267350361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1267350361 = 1699 ⋅745939.

It is a cyclic number.

It is not a de Polignac number, because 1630537621 - 2³ = 1630537613 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 (1630537121) 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, 388555 + ... + 392728.

It is an arithmetic number, because the mean of its divisors is an integer number (407830248).

Almost surely, 2^1630537621 is an apocalyptic number.

It is an amenable number.

1630537621 is a deficient number, since it is larger than the sum of its proper divisors (783371).

1630537621 is an equidigital number, since it uses as much as digits as its factorization.

1630537621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783370.

The product of its (nonzero) digits is 22680, while the sum is 34.

The square root of 1630537621 is about 40379.9160598434. The cubic root of 1630537621 is about 1177.0012964415.

Adding to 1630537621 its reverse (1267350361), we get a palindrome (2897887982).

The spelling of 1630537621 in words is "one billion, six hundred thirty million, five hundred thirty-seven thousand, six hundred twenty-one".