21419501 has 4 divisors (see below), whose sum is σ = 21561504. Its totient is φ = 21277500.

The previous prime is 21419491. The next prime is 21419513. The reversal of 21419501 is 10591412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21419501 - 2¹⁰ = 21418477 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 (21419551) 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, 70775 + ... + 71076.

It is an arithmetic number, because the mean of its divisors is an integer number (5390376).

Almost surely, 2^21419501 is an apocalyptic number.

It is an amenable number.

21419501 is a deficient number, since it is larger than the sum of its proper divisors (142003).

21419501 is a wasteful number, since it uses less digits than its factorization.

21419501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142002.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 21419501 is about 4628.1206769055. The cubic root of 21419501 is about 277.7174163895.

The spelling of 21419501 in words is "twenty-one million, four hundred nineteen thousand, five hundred one".