18761421 has 16 divisors (see below), whose sum is σ = 30271104. Its totient is φ = 10089984.

The previous prime is 18761389. The next prime is 18761423. The reversal of 18761421 is 12416781.

It is not a de Polignac number, because 18761421 - 2⁵ = 18761389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18761423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25920 + ... + 26633.

It is an arithmetic number, because the mean of its divisors is an integer number (1891944).

Almost surely, 2^18761421 is an apocalyptic number.

It is an amenable number.

18761421 is a deficient number, since it is larger than the sum of its proper divisors (11509683).

18761421 is a wasteful number, since it uses less digits than its factorization.

18761421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52580.

The product of its digits is 2688, while the sum is 30.

The square root of 18761421 is about 4331.4456016439. The cubic root of 18761421 is about 265.7185718962.

The spelling of 18761421 in words is "eighteen million, seven hundred sixty-one thousand, four hundred twenty-one".