21430761 has 16 divisors (see below), whose sum is σ = 33006528. Its totient is φ = 12224000.

The previous prime is 21430757. The next prime is 21430769. The reversal of 21430761 is 16703412.

It is a cyclic number.

It is not a de Polignac number, because 21430761 - 2² = 21430757 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21430769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18540 + ... + 19661.

It is an arithmetic number, because the mean of its divisors is an integer number (2062908).

Almost surely, 2^21430761 is an apocalyptic number.

It is an amenable number.

21430761 is a deficient number, since it is larger than the sum of its proper divisors (11575767).

21430761 is a wasteful number, since it uses less digits than its factorization.

21430761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38232.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21430761 is about 4629.3369935661. The cubic root of 21430761 is about 277.7660722119.

The spelling of 21430761 in words is "twenty-one million, four hundred thirty thousand, seven hundred sixty-one".