2137649621 has 4 divisors (see below), whose sum is σ = 2139838572. Its totient is φ = 2135460672.

The previous prime is 2137649617. The next prime is 2137649627. The reversal of 2137649621 is 1269467312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1593127396 + 544522225 = 39914^2 + 23335^2 .

It is a cyclic number.

It is not a de Polignac number, because 2137649621 - 2² = 2137649617 is a prime.

It is a super-2 number, since 2×2137649621² = 9139091804322887282, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2137649627) 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, 1093010 + ... + 1094963.

It is an arithmetic number, because the mean of its divisors is an integer number (534959643).

Almost surely, 2^2137649621 is an apocalyptic number.

It is an amenable number.

2137649621 is a deficient number, since it is larger than the sum of its proper divisors (2188951).

2137649621 is an equidigital number, since it uses as much as digits as its factorization.

2137649621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188950.

The product of its digits is 108864, while the sum is 41.

The square root of 2137649621 is about 46234.7231093688. The cubic root of 2137649621 is about 1288.1867883382.

The spelling of 2137649621 in words is "two billion, one hundred thirty-seven million, six hundred forty-nine thousand, six hundred twenty-one".