21404552340 has 48 divisors (see below), whose sum is σ = 59939889408. Its totient is φ = 5707200384.

The previous prime is 21404552317. The next prime is 21404552401. The reversal of 21404552340 is 4325540412.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21404552298 and 21404552307.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 674674 + ... + 705686.

It is an arithmetic number, because the mean of its divisors is an integer number (1248747696).

Almost surely, 2^21404552340 is an apocalyptic number.

21404552340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21404552340 is an abundant number, since it is smaller than the sum of its proper divisors (38535337068).

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

21404552340 is a wasteful number, since it uses less digits than its factorization.

21404552340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42528 (or 42526 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The spelling of 21404552340 in words is "twenty-one billion, four hundred four million, five hundred fifty-two thousand, three hundred forty".