81435711554 has 4 divisors (see below), whose sum is σ = 122153567334. Its totient is φ = 40717855776.

The previous prime is 81435711521. The next prime is 81435711587. The reversal of 81435711554 is 45511753418.

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

It is an interprime number because it is at equal distance from previous prime (81435711521) and next prime (81435711587).

It can be written as a sum of positive squares in only one way, i.e., 75637650529 + 5798061025 = 275023^2 + 76145^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20358927887 + ... + 20358927890.

Almost surely, 2^81435711554 is an apocalyptic number.

81435711554 is a deficient number, since it is larger than the sum of its proper divisors (40717855780).

81435711554 is a wasteful number, since it uses less digits than its factorization.

81435711554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40717855779.

The product of its digits is 336000, while the sum is 44.

The spelling of 81435711554 in words is "eighty-one billion, four hundred thirty-five million, seven hundred eleven thousand, five hundred fifty-four".