21554120031 has 8 divisors (see below), whose sum is σ = 29035103664. Its totient is φ = 14221274880.

The previous prime is 21554119967. The next prime is 21554120033. The reversal of 21554120031 is 13002145512.

It is a happy number.

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

It is not a de Polignac number, because 21554120031 - 2⁶ = 21554119967 is a prime.

It is a super-2 number, since 2×21554120031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21554119983 and 21554120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554120033) 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, 37034280 + ... + 37034861.

It is an arithmetic number, because the mean of its divisors is an integer number (3629387958).

Almost surely, 2^21554120031 is an apocalyptic number.

21554120031 is a deficient number, since it is larger than the sum of its proper divisors (7480983633).

21554120031 is an equidigital number, since it uses as much as digits as its factorization.

21554120031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74069241.

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 21554120031 its reverse (13002145512), we get a palindrome (34556265543).

The spelling of 21554120031 in words is "twenty-one billion, five hundred fifty-four million, one hundred twenty thousand, thirty-one".