21011222078 has 32 divisors (see below), whose sum is σ = 39305952000. Its totient is φ = 8183640960.

The previous prime is 21011222077. The next prime is 21011222081. The reversal of 21011222078 is 87022211012.

It is a super-2 number, since 2×21011222078² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011222077) 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, 519350 + ... + 558342.

It is an arithmetic number, because the mean of its divisors is an integer number (1228311000).

Almost surely, 2^21011222078 is an apocalyptic number.

21011222078 is a deficient number, since it is larger than the sum of its proper divisors (18294729922).

21011222078 is a wasteful number, since it uses less digits than its factorization.

21011222078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42512.

The product of its (nonzero) digits is 896, while the sum is 26.

The spelling of 21011222078 in words is "twenty-one billion, eleven million, two hundred twenty-two thousand, seventy-eight".