21400352154 has 24 divisors (see below), whose sum is σ = 46792823220. Its totient is φ = 7068005568.

The previous prime is 21400352069. The next prime is 21400352159. The reversal of 21400352154 is 45125300412.

It can be written as a sum of positive squares in 2 ways, for example, as 17140831929 + 4259520225 = 130923^2 + 65265^2 .

It is not an unprimeable number, because it can be changed into a prime (21400352159) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5451747 + ... + 5455670.

Almost surely, 2^21400352154 is an apocalyptic number.

21400352154 is an abundant number, since it is smaller than the sum of its proper divisors (25392471066).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21400352154 is a wasteful number, since it uses less digits than its factorization.

21400352154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10907534 (or 10907531 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21400352154 its reverse (45125300412), we get a palindrome (66525652566).

The spelling of 21400352154 in words is "twenty-one billion, four hundred million, three hundred fifty-two thousand, one hundred fifty-four".