21890124531 has 24 divisors (see below), whose sum is σ = 35771072064. Its totient is φ = 13266740520.

The previous prime is 21890124517. The next prime is 21890124533. The reversal of 21890124531 is 13542109812.

21890124531 is a `hidden beast` number, since 2 + 18 + 90 + 1 + 24 + 531 = 666.

It is not a de Polignac number, because 21890124531 - 2⁶ = 21890124467 is a prime.

It is a super-2 number, since 2×21890124531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21890124533) 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, 4092001 + ... + 4097346.

It is an arithmetic number, because the mean of its divisors is an integer number (1490461336).

Almost surely, 2^21890124531 is an apocalyptic number.

21890124531 is a deficient number, since it is larger than the sum of its proper divisors (13880947533).

21890124531 is an equidigital number, since it uses as much as digits as its factorization.

21890124531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8189373 (or 8189361 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 21890124531 in words is "twenty-one billion, eight hundred ninety million, one hundred twenty-four thousand, five hundred thirty-one".