21780939370 has 32 divisors (see below), whose sum is σ = 41421530880. Its totient is φ = 8223353280.

The previous prime is 21780939337. The next prime is 21780939371. The reversal of 21780939370 is 7393908712.

It is not an unprimeable number, because it can be changed into a prime (21780939371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 160017 + ... + 262996.

It is an arithmetic number, because the mean of its divisors is an integer number (1294422840).

Almost surely, 2^21780939370 is an apocalyptic number.

21780939370 is a deficient number, since it is larger than the sum of its proper divisors (19640591510).

21780939370 is a wasteful number, since it uses less digits than its factorization.

21780939370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423310.

The product of its (nonzero) digits is 571536, while the sum is 49.

The spelling of 21780939370 in words is "twenty-one billion, seven hundred eighty million, nine hundred thirty-nine thousand, three hundred seventy".