20212155551 has 8 divisors (see below), whose sum is σ = 23105016480. Its totient is φ = 17320647168.

The previous prime is 20212155541. The next prime is 20212155553. The reversal of 20212155551 is 15555121202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20212155551 is a prime.

It is a super-2 number, since 2×20212155551² (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 (20212155553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305906 + ... + 366063.

It is an arithmetic number, because the mean of its divisors is an integer number (2888127060).

Almost surely, 2^20212155551 is an apocalyptic number.

20212155551 is a deficient number, since it is larger than the sum of its proper divisors (2892860929).

20212155551 is an equidigital number, since it uses as much as digits as its factorization.

20212155551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676273.

The product of its (nonzero) digits is 5000, while the sum is 29.

Adding to 20212155551 its reverse (15555121202), we get a palindrome (35767276753).

The spelling of 20212155551 in words is "twenty billion, two hundred twelve million, one hundred fifty-five thousand, five hundred fifty-one".