20505015602 has 4 divisors (see below), whose sum is σ = 30757523406. Its totient is φ = 10252507800.

The previous prime is 20505015577. The next prime is 20505015649. The reversal of 20505015602 is 20651050502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20651050502 = 2 ⋅10325525251.

It can be written as a sum of positive squares in only one way, i.e., 15530393641 + 4974621961 = 124621^2 + 70531^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5126253899 + ... + 5126253902.

Almost surely, 2^20505015602 is an apocalyptic number.

20505015602 is a deficient number, since it is larger than the sum of its proper divisors (10252507804).

20505015602 is a wasteful number, since it uses less digits than its factorization.

20505015602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10252507803.

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 20505015602 in words is "twenty billion, five hundred five million, fifteen thousand, six hundred two".