21420401376 has 48 divisors (see below), whose sum is σ = 61340243328. Its totient is φ = 6491030400.

The previous prime is 21420401371. The next prime is 21420401383. The reversal of 21420401376 is 67310402412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420401371) 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, 10141180 + ... + 10143291.

It is an arithmetic number, because the mean of its divisors is an integer number (1277921736).

Almost surely, 2^21420401376 is an apocalyptic number.

It is an amenable number.

21420401376 is an abundant number, since it is smaller than the sum of its proper divisors (39919841952).

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

21420401376 is a wasteful number, since it uses less digits than its factorization.

21420401376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20284495 (or 20284487 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

Adding to 21420401376 its reverse (67310402412), we get a palindrome (88730803788).

The spelling of 21420401376 in words is "twenty-one billion, four hundred twenty million, four hundred one thousand, three hundred seventy-six".