20402151551 has 4 divisors (see below), whose sum is σ = 21060285504. Its totient is φ = 19744017600.

The previous prime is 20402151529. The next prime is 20402151593. The reversal of 20402151551 is 15515120402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20402151551 - 2¹⁴ = 20402135167 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20402151551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402151521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329066930 + ... + 329066991.

It is an arithmetic number, because the mean of its divisors is an integer number (5265071376).

Almost surely, 2^20402151551 is an apocalyptic number.

20402151551 is a deficient number, since it is larger than the sum of its proper divisors (658133953).

20402151551 is an equidigital number, since it uses as much as digits as its factorization.

20402151551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658133952.

The product of its (nonzero) digits is 2000, while the sum is 26.

Adding to 20402151551 its reverse (15515120402), we get a palindrome (35917271953).

The spelling of 20402151551 in words is "twenty billion, four hundred two million, one hundred fifty-one thousand, five hundred fifty-one".