15406045621 has 4 divisors (see below), whose sum is σ = 15454645452. Its totient is φ = 15357445792.

The previous prime is 15406045601. The next prime is 15406045649. The reversal of 15406045621 is 12654060451.

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 1076758596 + 14329287025 = 32814^2 + 119705^2 .

It is a cyclic number.

It is not a de Polignac number, because 15406045621 - 2¹⁹ = 15405521333 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 (15406045601) 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, 24299440 + ... + 24300073.

It is an arithmetic number, because the mean of its divisors is an integer number (3863661363).

Almost surely, 2^15406045621 is an apocalyptic number.

It is an amenable number.

15406045621 is a deficient number, since it is larger than the sum of its proper divisors (48599831).

15406045621 is an equidigital number, since it uses as much as digits as its factorization.

15406045621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48599830.

The product of its (nonzero) digits is 28800, while the sum is 34.

The spelling of 15406045621 in words is "fifteen billion, four hundred six million, forty-five thousand, six hundred twenty-one".