21621402154325 has 24 divisors (see below), whose sum is σ = 26822618659200. Its totient is φ = 17289330068160.

The previous prime is 21621402154321. The next prime is 21621402154349. The reversal of 21621402154325 is 52345120412612.

It is not a de Polignac number, because 21621402154325 - 2² = 21621402154321 is a prime.

It is a super-2 number, since 2×21621402154325² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621402154321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 579503771 + ... + 579541079.

It is an arithmetic number, because the mean of its divisors is an integer number (1117609110800).

Almost surely, 2^{21621402154325} is an apocalyptic number.

21621402154325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21621402154325 is a deficient number, since it is larger than the sum of its proper divisors (5201216504875).

21621402154325 is a wasteful number, since it uses less digits than its factorization.

21621402154325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47141 (or 47136 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 38.

Adding to 21621402154325 its reverse (52345120412612), we get a palindrome (73966522566937).

The spelling of 21621402154325 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred two million, one hundred fifty-four thousand, three hundred twenty-five".