21406440770 has 192 divisors, whose sum is σ = 47955369600. Its totient is φ = 6809886720.

The previous prime is 21406440733. The next prime is 21406440779. The reversal of 21406440770 is 7704460412.

It is a self number, because there is not a number n which added to its sum of digits gives 21406440770.

It is not an unprimeable number, because it can be changed into a prime (21406440779) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 31807154 + ... + 31807826.

It is an arithmetic number, because the mean of its divisors is an integer number (249767550).

Almost surely, 2^21406440770 is an apocalyptic number.

21406440770 is an abundant number, since it is smaller than the sum of its proper divisors (26548928830).

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

21406440770 is a wasteful number, since it uses less digits than its factorization.

21406440770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 35.

The spelling of 21406440770 in words is "twenty-one billion, four hundred six million, four hundred forty thousand, seven hundred seventy".