21254016355290 has 48 divisors (see below), whose sum is σ = 55261384994088. Its totient is φ = 5667641031168.

The previous prime is 21254016355219. The next prime is 21254016355291. The reversal of 21254016355290 is 9255361045212.

21254016355290 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 4 + 0 + 1 + 6 + 3 + 552 + 90 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 10901150252721 + 10352866102569 = 3301689^2 + 3217587^2 .

It is a super-2 number, since 2×21254016355290² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21254016355291) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3372102 + ... + 7340238.

Almost surely, 2^{21254016355290} is an apocalyptic number.

21254016355290 is an abundant number, since it is smaller than the sum of its proper divisors (34007368638798).

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

21254016355290 is a wasteful number, since it uses less digits than its factorization.

21254016355290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4027663 (or 4027660 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 45.

The spelling of 21254016355290 in words is "twenty-one trillion, two hundred fifty-four billion, sixteen million, three hundred fifty-five thousand, two hundred ninety".