1625620421 has 8 divisors (see below), whose sum is σ = 1631768664. Its totient is φ = 1619481600.

The previous prime is 1625620313. The next prime is 1625620463. The reversal of 1625620421 is 1240265261.

It can be written as a sum of positive squares in 4 ways, for example, as 16728100 + 1608892321 = 4090^2 + 40111^2 .

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 1625620421 - 2¹⁰ = 1625619397 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 (1625620921) 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, 634475 + ... + 637031.

It is an arithmetic number, because the mean of its divisors is an integer number (203971083).

Almost surely, 2^1625620421 is an apocalyptic number.

It is an amenable number.

1625620421 is a deficient number, since it is larger than the sum of its proper divisors (6148243).

1625620421 is a wasteful number, since it uses less digits than its factorization.

1625620421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4711.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 1625620421 is about 40318.9833825209. The cubic root of 1625620421 is about 1175.8169471219.

Adding to 1625620421 its reverse (1240265261), we get a palindrome (2865885682).

The spelling of 1625620421 in words is "one billion, six hundred twenty-five million, six hundred twenty thousand, four hundred twenty-one".