21451001532421 has 8 divisors (see below), whose sum is σ = 21498903607104. Its totient is φ = 21403120315680.

The previous prime is 21451001532391. The next prime is 21451001532509. The reversal of 21451001532421 is 12423510015412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21451001532421 - 2¹³ = 21451001524229 is a prime.

It is a super-3 number, since 3×21451001532421³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451001535421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3154416 + ... + 7269961.

It is an arithmetic number, because the mean of its divisors is an integer number (2687362950888).

Almost surely, 2^{21451001532421} is an apocalyptic number.

It is an amenable number.

21451001532421 is a deficient number, since it is larger than the sum of its proper divisors (47902074683).

21451001532421 is a wasteful number, since it uses less digits than its factorization.

21451001532421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10428971.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 21451001532421 its reverse (12423510015412), we get a palindrome (33874511547833).

The spelling of 21451001532421 in words is "twenty-one trillion, four hundred fifty-one billion, one million, five hundred thirty-two thousand, four hundred twenty-one".