20987490698 has 4 divisors (see below), whose sum is σ = 31481236050. Its totient is φ = 10493745348.

The previous prime is 20987490691. The next prime is 20987490737. The reversal of 20987490698 is 89609478902.

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

It can be written as a sum of positive squares in only one way, i.e., 13364978449 + 7622512249 = 115607^2 + 87307^2 .

It is a super-3 number, since 3×20987490698³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20987490698.

It is not an unprimeable number, because it can be changed into a prime (20987490691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5246872673 + ... + 5246872676.

Almost surely, 2^20987490698 is an apocalyptic number.

20987490698 is a deficient number, since it is larger than the sum of its proper divisors (10493745352).

20987490698 is a wasteful number, since it uses less digits than its factorization.

20987490698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10493745351.

The product of its (nonzero) digits is 15676416, while the sum is 62.

The spelling of 20987490698 in words is "twenty billion, nine hundred eighty-seven million, four hundred ninety thousand, six hundred ninety-eight".