21401012340 has 36 divisors (see below), whose sum is σ = 64916404644. Its totient is φ = 5706936576.

The previous prime is 21401012333. The next prime is 21401012341. The reversal of 21401012340 is 4321010412.

It can be written as a sum of positive squares in 2 ways, for example, as 8227941264 + 13173071076 = 90708^2 + 114774^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401012341) 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, 59447077 + ... + 59447436.

Almost surely, 2^21401012340 is an apocalyptic number.

21401012340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21401012340 is an abundant number, since it is smaller than the sum of its proper divisors (43515392304).

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

21401012340 is a wasteful number, since it uses less digits than its factorization.

21401012340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118894528 (or 118894523 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21401012340 its reverse (4321010412), we get a palindrome (25722022752).

The spelling of 21401012340 in words is "twenty-one billion, four hundred one million, twelve thousand, three hundred forty".