1972621 has 4 divisors (see below), whose sum is σ = 2254432. Its totient is φ = 1690812.

The previous prime is 1972613. The next prime is 1972627. The reversal of 1972621 is 1262791.

It is a happy number.

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: 1262791 = 487 ⋅2593.

It is a cyclic number.

It is not a de Polignac number, because 1972621 - 2³ = 1972613 is a prime.

It is the 1405-th Hogben number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1972621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1972627) by changing a digit.

It is a nontrivial repunit in base 1404.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140895 + ... + 140908.

It is an arithmetic number, because the mean of its divisors is an integer number (563608).

2^1972621 is an apocalyptic number.

It is an amenable number.

1972621 is a deficient number, since it is larger than the sum of its proper divisors (281811).

1972621 is an equidigital number, since it uses as much as digits as its factorization.

1972621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281810.

The product of its digits is 1512, while the sum is 28.

The square root of 1972621 is about 1404.5002669989. The cubic root of 1972621 is about 125.4145384102.

The spelling of 1972621 in words is "one million, nine hundred seventy-two thousand, six hundred twenty-one".