21430755 has 24 divisors (see below), whose sum is σ = 37571040. Its totient is φ = 11299200.

The previous prime is 21430753. The next prime is 21430757. The reversal of 21430755 is 55703412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21430753) and next prime (21430757).

It is not a de Polignac number, because 21430755 - 2¹ = 21430753 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430753) 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 23 ways as a sum of consecutive naturals, for example, 1330 + ... + 6680.

It is an arithmetic number, because the mean of its divisors is an integer number (1565460).

Almost surely, 2^21430755 is an apocalyptic number.

21430755 is a deficient number, since it is larger than the sum of its proper divisors (16140285).

21430755 is a wasteful number, since it uses less digits than its factorization.

21430755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5451 (or 5448 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21430755 is about 4629.3363455251. The cubic root of 21430755 is about 277.7660462897.

The spelling of 21430755 in words is "twenty-one million, four hundred thirty thousand, seven hundred fifty-five".