15420681 has 12 divisors (see below), whose sum is σ = 22318452. Its totient is φ = 10260096.

The previous prime is 15420677. The next prime is 15420707. The reversal of 15420681 is 18602451.

15420681 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

15420681 is a nontrivial binomial coefficient, being equal to C(5554, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 1245456 + 14175225 = 1116^2 + 3765^2 .

It is not a de Polignac number, because 15420681 - 2² = 15420677 is a prime.

It is a super-2 number, since 2×15420681² = 475594805007522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15420611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4165 + ... + 6941.

It is an arithmetic number, because the mean of its divisors is an integer number (1859871).

Almost surely, 2^15420681 is an apocalyptic number.

15420681 is the 5553-rd triangular number and also the 2777-th hexagonal number.

It is an amenable number.

15420681 is a deficient number, since it is larger than the sum of its proper divisors (6897771).

15420681 is a wasteful number, since it uses less digits than its factorization.

15420681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3400 (or 3397 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 15420681 is about 3926.9174934037. The cubic root of 15420681 is about 248.9055140612.

The spelling of 15420681 in words is "fifteen million, four hundred twenty thousand, six hundred eighty-one".