20461252649 has 4 divisors (see below), whose sum is σ = 21664855764. Its totient is φ = 19257649536.

The previous prime is 20461252621. The next prime is 20461252667. The reversal of 20461252649 is 94625216402.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12759961600 + 7701291049 = 112960^2 + 87757^2 .

It is a cyclic number.

It is not a de Polignac number, because 20461252649 - 2⁸ = 20461252393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20461252549) 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, 601801532 + ... + 601801565.

It is an arithmetic number, because the mean of its divisors is an integer number (5416213941).

Almost surely, 2^20461252649 is an apocalyptic number.

It is an amenable number.

20461252649 is a deficient number, since it is larger than the sum of its proper divisors (1203603115).

20461252649 is a wasteful number, since it uses less digits than its factorization.

20461252649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203603114.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 20461252649 in words is "twenty billion, four hundred sixty-one million, two hundred fifty-two thousand, six hundred forty-nine".