21464067640 has 32 divisors (see below), whose sum is σ = 48314854080. Its totient is φ = 8581946752.

The previous prime is 21464067631. The next prime is 21464067671. The reversal of 21464067640 is 4676046412.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 21464067593 and 21464067602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19552 + ... + 208111.

It is an arithmetic number, because the mean of its divisors is an integer number (1509839190).

Almost surely, 2^21464067640 is an apocalyptic number.

21464067640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21464067640 is an abundant number, since it is smaller than the sum of its proper divisors (26850786440).

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

21464067640 is a wasteful number, since it uses less digits than its factorization.

21464067640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230031 (or 230027 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 40.

The spelling of 21464067640 in words is "twenty-one billion, four hundred sixty-four million, sixty-seven thousand, six hundred forty".