21430641 has 32 divisors (see below), whose sum is σ = 31629312. Its totient is φ = 12862080.

The previous prime is 21430639. The next prime is 21430667. The reversal of 21430641 is 14603412.

It is not a de Polignac number, because 21430641 - 2¹ = 21430639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21430621) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 91861 + ... + 92093.

It is an arithmetic number, because the mean of its divisors is an integer number (988416).

Almost surely, 2^21430641 is an apocalyptic number.

It is an amenable number.

21430641 is a deficient number, since it is larger than the sum of its proper divisors (10198671).

21430641 is a wasteful number, since it uses less digits than its factorization.

21430641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21430641 is about 4629.3240327288. The cubic root of 21430641 is about 277.7655537673.

The spelling of 21430641 in words is "twenty-one million, four hundred thirty thousand, six hundred forty-one".