15420661 has 2 divisors, whose sum is σ = 15420662. Its totient is φ = 15420660.

The previous prime is 15420659. The next prime is 15420677. The reversal of 15420661 is 16602451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8820900 + 6599761 = 2970^2 + 2569^2 .

It is an emirp because it is prime and its reverse (16602451) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15420661 - 2¹ = 15420659 is a prime.

Together with 15420659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15420611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7710330 + 7710331.

It is an arithmetic number, because the mean of its divisors is an integer number (7710331).

Almost surely, 2^15420661 is an apocalyptic number.

It is an amenable number.

15420661 is a deficient number, since it is larger than the sum of its proper divisors (1).

15420661 is an equidigital number, since it uses as much as digits as its factorization.

15420661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 15420661 is about 3926.9149468762. The cubic root of 15420661 is about 248.9054064544.

The spelling of 15420661 in words is "fifteen million, four hundred twenty thousand, six hundred sixty-one".